Ford Integrated Relay Control Modules
Jimz466
Tempo. Eventually the problem was found to be a bad IRCM. These modules control
the fuel pump, engine cooling fan, air conditioning clutch and power to the car
ECM and cost $130 from Ford. I recently made a salvage yard run to get one of
these for a friends 94 Tempo. I grabbed a bunch, mostly from Taurus's. They
have all been tested and verified to work 100% in both the 94 Tempo and a 94
Taurus. If anyone needs one or wants a spare, you can have one for 20 bucks and
shipping cost.
Jim
Tim B
same on all vehicles. Even ones of the same make.
"Jimz466" <jim...@aol.com> wrote in message
news:20020921175923...@mb-md.aol.com...
Graham Shortt
inside.
Jdog
"Tim B" <ti...@telus.net> wrote in message news:wHaj9.21123$Zk4.9...@news2.telusplanet.net...I've noticed lots of people don't know about the calibration. They figure
if it looks the same it will work. Someone wanted to see what the inside
of one looks like. Ok here goes. Let's see if I can make it show just
below the writing. If it doesn't show up below the text maybe someone can
tell me how to do it. The insert picture option is greyed out.P.S. There was a transistor bolted to the right side. For some reason I ripped it off.
"Jimz466" <jim...@aol.com> wrote in message news:20020921175923...@mb-md.aol.com...
Jimz466
From what I have learned so far, there are (4) 40 amp relays inside the box.
These relays control power to the fuel pump, power to the ECM, power to the air
conditioning clutch and power to the engine cooling fan. I would appreciate
anyone explaining the differences in calibration to me, other than just a
blanket statement of "they have different calibrations, so they are not
interchangeable".
Maybe I am looking at things too simply, but to me, the fuel pump, ac clutch
and power to the ECM are either on or off. The only thing I can see being
different is when the cooling fan turns on and off, and I would not expect that
to be significantly different from one car to the next.
Like I said, I am willing to learn, and I am not intimately familiar with these
modules,so I am looking forward to a good explaination of the calibrations from
someone who is. Please, though, if you are only going to repeat the above
quote, save it for another day. I am truly interested in an explanation, not
just something that Ford is feeding into your head.
Thanks
Jim
Thomas H. Moats
news:u1mj9.263802$2L.10...@e3500-atl2.usenetserver.com...
> Inside the box are the 4 relays, but the different boxes contain relays
> with different resistances, depending on the system. Use the wrong one
and
> you could burn out your entire PCM system.
The supporting circuitry may be different, but the relays are the same.
>
> Even when the relays were separate you could practically interchange all
the
> relays on the vehicle, wiring would all fit, however the bottom of the
> relays were different colors indicating different relays with different
> resistances. Use the wrong one and you were in for more trouble than you
> started with.
>
The resistances were the same, what changed was the pin location and if the
relay was a single pole or two or normally open or normally closed and
weither or not a diode was in the relay. The processor also makes a ground
on the primary side, at that point the resistance means nothing as that the
ground part of the circuit voltage is 0.
> You will also find in the IRCM a circuit board, numerous diodes, voltage
> inverter and some computer chips.
Called supporting circuits.
These differ with application and
> calibration code.
>
> NO THE CALIBRATION CODE IS NOT SOMETHING FORD IS FEEDING INTO OUR HEAD, OR
> ALL THE OTHER AUTO MANUFACTURES FOR THAT MATTER.
>
> I did this before but I will "assume" you did not see the post.
>
> A calibration code tells what emission components are on your vehicle.
You
> could say it is a blueprint of your emission system. The same vehicle,
same
> powertrain, model year etc, can have 20 or more calibrations EACH YEAR
> depending on when it was built, where it was built, its destination, and
any
> updates and changes made throughout the year. This does not mean every
> component is different but many are changed. Use the wrong parts and you
> could cause more problems than you started out with.
>
> When you start changing years and even model lines you are literally
talking
> hundreds of different calibrations, different emission systems and
> components and the chances of them being the same are about nil.
>
> By looking up the calibration code the parts store, dealer etc can tell
> exactly what emission parts are in your vehicle. If you give them the
wrong
> calibration code you will receive the wrong part. It may look the same
but
> its operation, limits, resistances, are not the same.
>
> By replacing a component with one from a different calibration you are
also
> breaking federal law. Look at your owners manual. It is even stated in
> there.
>
> For my 2000 Taurus it is stated on page 188 and 189 where it says
> "do not make any unauthorized changes to your vehicle or engine. By law
> vehicle owners and anyone who manufacturers, repairs, services, sells,
> leases, trades vehicles, or supervises a fleet of vehicles are not
permitted
> to intentionally remove an emission control device or prevent it from
> working."
>
> By using the wrong parts you are preventing the system from working the
way
> it was designed.
>
> All emission components replaced on your vehicle must be for your vehicles
> emission system. The parts are listed according to calibration code. I
do
> not think I can put any clearer.
>
> Did this help any?
>
> JL
>
>
>
>
>
>
>
> "Jimz466" <jim...@aol.com> wrote in message
> news:20020922003832...@mb-md.aol.com...
Jimz466
different resistances from year to year and model to model? Being an
electronics technician/muticraft technician for the last 17 years, I can buy
into the support circuitry being different, but not the relays. Relays are just
switches and are not designed with an internal resistance. They would burn up.
A 40 amp relay with any internal resistance would smoke with only a couple amps
going thru it. P=I^2R with only 10 amps and 1 ohm resistance , the relay would
generate 100 watts as heat. Go grab a 100watt soldering iron (if you can find
one that big) and let me know how it feels. It would also drop 10 volts,
leaving only 2 volts for the load being supplied.
My next question is: Is this module listed as an emission control device? Can
this module have any effect on emissions other than a minor change in engine
temp if the cooling fan setpoints are different?
#1. Controls power to fuel pump -can this change emmisions?
#2 Controls power to ECM-can this change emmissions?
#3 Controls power to AC clutch- can this change emmissions?
#4 Controls power to cooling fan-may make engine run richer/leaner depending on
coolant temperature, but does an electric fan really run while car is in
motion? If it does, you probably have other problems.
Someone also mentioned they got one from a junkyard for 10 bucks and now they
have a check engine light and get bad gas milage. Have they scanned the code to
find out what the problem is? I would be interested in knowing what code comes
up.
Like I said before, this is a learning experience for me. I don't normally fool
around with late model cars so please don't feel like I am being a dick or
anything, just trying to learn.
Jim
Thomas H. Moats
> OK, not to start an arguement, but you are saying that these relays have
> different resistances from year to year and model to model? Being an
> electronics technician/muticraft technician for the last 17 years, I can
buy
> into the support circuitry being different, but not the relays.
Smell like some one is trying to blow smoke? I smell it too.
> Relays are just
> switches and are not designed with an internal resistance. They would burn
up.
> A 40 amp relay with any internal resistance would smoke with only a couple
amps
> going thru it. P=I^2R with only 10 amps and 1 ohm resistance , the relay
would
> generate 100 watts as heat. Go grab a 100watt soldering iron (if you can
find
> one that big) and let me know how it feels. It would also drop 10 volts,
> leaving only 2 volts for the load being supplied.
Well said.
> My next question is: Is this module listed as an emission control device?
No, calibration has nothing to do with the part in question.
>Can
> this module have any effect on emissions other than a minor change in
engine
> temp if the cooling fan setpoints are different?
Zero effect. The part in question does not even care at what temperatures it
turns on and off the cooling fan, being it is not what decides that. It is
nothing more than a slave device.
> #1. Controls power to fuel pump -can this change emmisions?
No.
> #2 Controls power to ECM-can this change emmissions?
No.
> #3 Controls power to AC clutch- can this change emmissions?
No.
> #4 Controls power to cooling fan-may make engine run richer/leaner
depending on
> coolant temperature, but does an electric fan really run while car is in
> motion?
No, the processor decides fuel mixture.
>If it does, you probably have other problems.
Which is why that person most likely has the MIL on. The real reason the
part number changed through the years is how the circuitry is put together.
Changes in design that gives better life, things of that matter. If you get
a chance, find a schematic for the vehicles that use the module and compare,
you will find they are the same.
Thomas H. Moats
> JimZ,
>
> As for the IRCM not having anything to do with the emission system I would
> think that supplying the power to the system would qualify as a "LITTLE"
> something.
>
> JL
>
>
Does an eec relay fall under emission? No, and it does supply power to the
processor. The IRCM, does not. It is a slave device, like a
relay..........oh gee, I forgot, it is a relay.
Thomas H. Moats
> Relays have windings that create the magnetic field that closes or opens
the
> circuit depending on if it is normally open or closed. Different relays
> have different amount of windings and therefore different resistances.
Ford
> put our a warning years ago maybe before your 17 years since I have been
a
> master tech for over 30 years, that the relays are not to be interchanged.
> If they were all the same why would they make different relays with
> different part numbers. They all had the same connector.
>
If I ask you, I'm sure your will say you do not have the information any
more. But for what it is worth, Ford made a change in most of the coil wound
devices, they put diodes in them. That made the backward compatible, and
made the old ones obsolete on anything after that point in time. The most
notable is the idle speed solenoid. Other wise the winding resistances were
the same. That is what the "warning" was about. After that Ford went to Bosh
style relays, most all of them have the same part number and are fully
interchangeable. It was even taught in Ford Service schools to swap relays
when one is suspect.
Jimz466
>
Maybe we are? I just popped an IRCM open today. Part number E7DF-12B577-CB. E7
was the oldest I have. It contains 4 BOSCH relays. All have the same bosch part
number (0 332 014 162) and the same ford part number (E6DF14A60CA). I'll see if
my friend has the old one we replaced. It was a F2 IIRC. I assumed it was
tossed, but you never know. If he has it, I'll pull it apart.
And also, speaking of coils. The size of the coil is determined by the size of
the relay contact arms which are required to be pulled together (or apart).
Larger relays have physically larger contacts and linkage arms and require a
larger coil to generate the necessary magnetic field strength. More coils of
wire can generate a stronger field, but will not necessarily draw significantly
more or less current. Considering these little black box ice cube relays are
operated by current from another magic box, it only takes milliamps to activate
the coil mag field.
OK, just measured one. Had to test out a brand new meter. The coil measures at
86.5 ohms. This would give a current draw (12v) of about 135 milliamps upon
application of power to the circuit. Subject to some variation after mag field
builds up.
And, speaking of diodes? When the power to the coil goes away, what happens to
the mag field? That mag field is energy. That energy has to go somewhere.
Thomas H. Moats
following you lately correcting Your correct information? For some one who
has 30 years as a master with service manager and shop Forman experience,
something just does not add up.news:kVtj9.265903$2L.10...@e3500-atl2.usenetserver.com...
> Oh I give up. I know what I was taught by Ford. You don't want to
believe
> it fine with me.
> I am only here trying to help people who need help to get the correct
> information for a change.
>
> But then I ask myself Why should I care. After they are screwed up
almost
> beyond repair they are going to bring it to the dealer anyway.
>
> JL
>
>
> "Thomas H. Moats" <tmo...@comcast.net> wrote in message
> news:YCpj9.214462$5r1.8...@bin5.nnrp.aus1.giganews.com...
Aron
going back through the driver. When a coil is energized it creates a
magnetic field. When the power is disconnected the field decays. The
changing field (change in flux density, I believe - yes magnetic flux is a
real thing, I didn't say flux capacitor) creates current in the coil, just
like moving a magnet trough a coil. Many ignition coils work this way
(field decay type rather than capacitive discharge). You can get a lot of
voltage out of a rely or any inductive load. These high voltages are
troublesome to microprocessors and their CMOS technology friends, among
other semiconductor devices.
Someone said that the relay coil circuit is completed by the EEC
connecting the coil to ground. They said that this meant that the coil
resistance didn't really matter. That isn't really true. The resistance in
the coil effects the amount of current flowing through the circuit between
the power source and return (ground). How do you think the connection to
ground is made? It is done through some kind of driver that involves a
solid state device, such as a transistor. Changing the coil resistance
changes the current through the driver by changing the total impedance of
the loop. If the current is raised too far out of spec it will burn this
part up or wear it out faster. This can happen even when talking about
small currents, like that calculated 135mA in a previous post, if the driver
circuit isn't designed for it.
From the conservative standpoint of Ford (and J. Louis) replacing a part
with the same part number will always work and is all that should be done
because it isn't a gamble. There is that chance that you get that relay
that by design is so far off from what your car was designed for that things
fry. In theory there should be some safeties and circuit protection but you
can't count on that because they designed the system expecting the part to
be replaced by the same part. There may be protection against problems
likely during normal operation but they aren't necessarily going to protect
against tampering. It is realistic that a relay of the same size will work
in the same circuit though since it is possible for variances within a brand
to be as extreme as variances between brands. There are always exceptions.
This isn't a hit, J., I just think that while some people would be saying
hold my beer and watch this, you would be making sure your beer is securely
in the cup holder before reading the manual. Believe me, I can appreciate
that, especially if I'm getting my car serviced by you. I know I won't be
finding any twist ties in there holding things together. This is a very
good thing when paying a premium for work at a dealer. Any Ford dealer that
I've been to around here has been like a glorified gas station. Why aren't
their techs as conscientious? I would really like to know.
On the other hand, a lot of people here don't want to put any money into
their car. I certainly can't see $130 for a couple switches. I can't see
what great engineering challenges are involved. I also believe that this
calibration stuff is a crock to some extent. I believe that Ford will
change the number on this module because they changed what brand of
injectors they used in that production run.
If you could open these units easily you could look and see if they're the
same inside but they don't want you to find that out. They want you to live
in fear of burning out your PCM so you'll fork over that $130. And to avoid
liability with no effort they will say that only one with the same number
should be used because that's the number the system was designed for.
Meanwhile the truth may be that the next "calibration" has no differences in
this module except a diode that would actually save your older system.
I think we need to solve the riddle of the IRCMs. It's too much
controversy, price, and bull over a little black box that completes the
circuit to a few basic things, don't you think? I think that Ford found an
excuse to make it a bigger deal than it is by finding an excuse to call it
part of the emissions. Either that or they exploited federal regulations
imposed on their previous set up. Either way, by making it such a big deal
and completely mysterious they've got almost guaranteed control.
I think that the relays aren't a big deal because relays are not very
different when within the same rating range. The diodes across the relays
are good to have. I don't know why some have them and some don't. Perhaps
the circuits that don't have them can take a voltage spike, maybe they
aren't digitally (or should I say microprocessor) controlled circuits. Now
the question is, what about this other support circuitry? Is it for timing?
Is it for current limiting? Could be. Let's do more research.
I am part yahoo and part conservative myself. I think "no user
serviceable parts" usually depends on the user, yet I tend to read the
manual when available. The manual doesn't really say what's in these. I
was hoping to get some answers on that from here myself. Well I've gotten
some, but maybe it's time to get out the hacksaw (or is there a better way
to get into these units). If any of you guys that have ripped these apart
have good pictures let me see them.
Does anyone in the CT area have some of these that are working and opened
or any unopened that they're willing to possibly destroy by opening and
would like to help further the research? Let me know. I would like to
analyze a few myself. I have a lot of applicable experience. I think the
group is hungry to know the truth about these and I think there's only one
way to find out for sure. We can put our experience together and get the
answers.
I wonder what the compatibility software junk yards use has to say about
these. I'm not going to just say these things are compatible, that would be
irresponsible, but I bet a lot of them are, regardless of what Ford says.
They have their own interests, we have ours. No one seems to be a pro on th
ese, so post what you know and eventually we'll figure it all out.
"Jimz466" <jim...@aol.com> wrote in message
news:20020922232344...@mb-fi.aol.com...
Jimz466
>have good pictures let me see them
You have mail. Feel free to post them for the group.
Jim
Thomas H. Moats
"Tim B" <ti...@telus.net> wrote in message news:wHaj9.21123$Zk4.9...@news2.telusplanet.net...I've noticed lots of people don't know about the calibration. They figure
if it looks the same it will work. Someone wanted to see what the inside
of one looks like. Ok here goes. Let's see if I can make it show just
below the writing. If it doesn't show up below the text maybe someone can
tell me how to do it. The insert picture option is greyed out.P.S. There was a transistor bolted to the right side. For some reason I ripped it off.
"Jimz466" <jim...@aol.com> wrote in message news:20020921175923...@mb-md.aol.com...
Thomas H. Moats
> I have always respected you, why are you attacking me.
I'm not attacking you. Read my posts.
>You seem jealous of
> my certifications and qualifications?
Thats even funnier! I have at least as menay as you, if not more.
> You keep bringing them up. I only
> bring them up when asked.
You have offered your "resume" many times proclaiming who you are.
> If we have different opinions on a repair so
> what,
I have not corrected you on repair "opinions", only your incorrect
information like the TOT sensor you called a switch and went as far as
explaining it as a switch.
> Let the newsreader do the checks and find out who is correct. I Just
> don't waste my time arguing with you.
>
> I have never lied to anyone about my credentials, work experience, or
> ANYTHING else for that matter. I don't lie. You it seems with no
training,
> an ego the size of Texas and technical experience the size of a mustard
seed
> is what does not add up.
>
Really? TOT sensor, mister 30 years, mister sparkplug on a emission test.
> You cant even figure out emission laws and the major effect they have on
> auto repair.
You apparently missed the laws I posted, NY state laws. Which completely
contradicted what you said. If you remember I asked you if you and
regulation numbers for what you stated. You conviently said you no longer
had the information. So I'll repost it for you.
http://www.nydmv.state.ny.us/vehsafe.htm#einspect
That is just two.
> Don't consider the readers safety or their ability. You
> ignore warnings that state unless you have the training DO NOT attempt
this
> repair take it to a qualified repair shop.
You also apparently miss the many times I advise people to take it to a
qualified shop.
> I don't want anyone to get
> hurt, you don't seem to care at all.
>
> Don't consider a part that is even called by name of the emission system a
> part of the system. FYI ANYTHING that has any effect on the EEC system is
> considered part of the system. But I guess you would not know that, your
> ego is blocking your view.
>
Read the law. It clearly defines what is an emission part.
This is California, which NY adopted.
TITLE 13. Motor Vehicles
Division 3. Air Resources Board
Chapter 1. Motor Vehicle Pollution Control Devices
Article 2. Approval of Motor Vehicle Pollution Control Devices
(New Vehicles)
§1968. Malfunction and Diagnostic System for
1988 and Subsequent Model Year Passenger Cars, Light-Duty Trucks, and
Medium-Duty Vehicles with Three-Way Catalyst Systems and Feedback Control.
(2) "Malfunction" means the partial or total failure of one or more
computer-sensed emission-related components or the on-board computer
processor, or of the emission-related functioning of a fuel metering device
or EGR system to a degree which would likely cause the emissions of an
average certification vehicle with the failure or failures, individually or
in combination, to exceed the emissions standards applicable pursuant to
Subchapter 1 (commencing with Section 1900), Chapter 3 of Title 13.
This Is NY.
6 NYCRR Part 218, Emission Standards For Motor Vehicles And Motor Vehicle
Engines
(c) "Air contaminant emission control system" means equipment designed for
installation on a motor vehicle or motor vehicle engine for the purpose of
reducing the air contaminants emitted from the motor vehicle or motor
vehicle engine, or a system or engine modification on a motor vehicle or
motor vehicle engine which causes a reduction of air contaminants emitted
from the motor vehicle or motor vehicle engine, including but not limited to
exhaust control systems, fuel evaporation control systems and crankcase
ventilating systems.
(d) "California Standards" means those standards for motor [vehicle]
vehicles and motor vehicle engines that the State of California has adopted
and is permitted to adopt under 42 USC 7543 (see Table 1, section 200.9 of
this Title) and that other states are permitted to adopt under 42 USC 7507
(see Table 1, section 200.9 of this Title).
The fact is a worn plug can cause high emissions, so can a worn cam, worn
piston rings ect. Only if the vehicle fails the test or tests do you search
for the cause. A plug that is out of the proper heat range eventually will
either foul out or melt. Until that happens it will not cause high
emissions.
> I think you have been spending too much time with hurricane, you are
> beginning to act just like him. Going to start calling you two the windy
> hot air brothers.
>
> Well, I will not respond anymore to any of your untrained egotistical hot
> air.
I will follow you and correct any information you give, so make sure you are
correct.
>
> Have a nice life,
>
> JL
>
>
>
BTW, 90,01 model years Bosh style relays were used across the board. If you
were really a tech, you would know that.
Thomas H. Moats
news:lLLj9.10332$XE1.9...@newsread2.prod.itd.earthlink.net...
> He is correct about the diodes. The diodes prevent voltage spikes from
> going back through the driver. When a coil is energized it creates a
> magnetic field. When the power is disconnected the field decays. The
> changing field (change in flux density, I believe - yes magnetic flux is a
> real thing, I didn't say flux capacitor) creates current in the coil, just
> like moving a magnet trough a coil. Many ignition coils work this way
> (field decay type rather than capacitive discharge). You can get a lot of
> voltage out of a rely or any inductive load. These high voltages are
> troublesome to microprocessors and their CMOS technology friends, among
> other semiconductor devices.
>
That is why Ford has so many diodes in the harness as well as in coil wound
parts now.
> Someone said that the relay coil circuit is completed by the EEC
> connecting the coil to ground. They said that this meant that the coil
> resistance didn't really matter. That isn't really true. The resistance
in
> the coil effects the amount of current flowing through the circuit between
> the power source and return (ground).
Current will only go as high as needed to over come the load. The resistance
of the coil is the primary load, after the load ( ground ) current will only
be high enough to go to ground. The only real resistance in the circuit that
matters after the load is ground after the transistor. If the ground is poor
current will be high enough to overcome that resistance, which could be high
enough to damage the transistor.
> How do you think the connection to
> ground is made? It is done through some kind of driver that involves a
> solid state device, such as a transistor. Changing the coil resistance
> changes the current through the driver by changing the total impedance of
> the loop.
Read above statement.
Ford has never called it an emission part. If you were to look up in the
emission warranty parts list, it is not in there.
I don't understand why Ford used this device as well. Only
Taurus/Sable/Continental and the last few model years of Tempo/Topaz used
it. Everything else worked just fine with stand alone relays.
>Either that or they exploited federal regulations
> imposed on their previous set up. Either way, by making it such a big
deal
> and completely mysterious they've got almost guaranteed control.
>
> I think that the relays aren't a big deal because relays are not very
> different when within the same rating range. The diodes across the relays
> are good to have. I don't know why some have them and some don't.
Perhaps
That is evolution. EEC3 had very little diode protection.
> the circuits that don't have them can take a voltage spike, maybe they
> aren't digitally (or should I say microprocessor) controlled circuits.
Now
> the question is, what about this other support circuitry? Is it for
timing?
> Is it for current limiting? Could be. Let's do more research.
>
That would be a good question, the models that do not use the "black box" do
not have all the supporting circuitry. I suspect some vendor made a killing.
> I am part yahoo and part conservative myself. I think "no user
> serviceable parts" usually depends on the user, yet I tend to read the
> manual when available. The manual doesn't really say what's in these. I
> was hoping to get some answers on that from here myself. Well I've gotten
> some, but maybe it's time to get out the hacksaw (or is there a better way
> to get into these units).
Just drill out the two rivets at the corners. Depending on year you will
either have Siemens relays or Bosch. Four in all. One power resister about
(62 ohms) The rest is just capacitors, resisters and what looks like could
be transistors or voltage regulators ( I haven't taken the time to look up
the numbers )
> If any of you guys that have ripped these apart
> have good pictures let me see them.
Take a look. This is from an 89 Sable. The relay for the fuel pump is open.
I have not found any other problem with it.
>
> Does anyone in the CT area have some of these that are working and
opened
> or any unopened that they're willing to possibly destroy by opening and
> would like to help further the research? Let me know. I would like to
> analyze a few myself. I have a lot of applicable experience. I think the
> group is hungry to know the truth about these and I think there's only one
> way to find out for sure. We can put our experience together and get the
> answers.
>
> I wonder what the compatibility software junk yards use has to say about
> these. I'm not going to just say these things are compatible, that would
be
> irresponsible, but I bet a lot of them are, regardless of what Ford says.
> They have their own interests, we have ours. No one seems to be a pro on
th
> ese, so post what you know and eventually we'll figure it all out.
>
>
>
----------------------------------------------------------------------------
----
Thomas H. Moats
news:lLLj9.10332$XE1.9...@newsread2.prod.itd.earthlink.net...
> going back through the driver. When a coil is energized it creates a
> magnetic field. When the power is disconnected the field decays. The
> changing field (change in flux density, I believe - yes magnetic flux is a
> real thing, I didn't say flux capacitor) creates current in the coil, just
> like moving a magnet trough a coil. Many ignition coils work this way
> (field decay type rather than capacitive discharge). You can get a lot of
> voltage out of a rely or any inductive load. These high voltages are
> troublesome to microprocessors and their CMOS technology friends, among
> other semiconductor devices.
>
That is why Ford has so many diodes in the harness as well as in coil wound
parts now.
> Someone said that the relay coil circuit is completed by the EEC
> connecting the coil to ground. They said that this meant that the coil
> resistance didn't really matter. That isn't really true. The resistance
in
> the coil effects the amount of current flowing through the circuit between
> the power source and return (ground).
Current will only go as high as needed to over come the load. The resistance
of the coil is the primary load, after the load ( ground ) current will only
be high enough to go to ground. The only real resistance in the circuit that
matters after the load is ground after the transistor. If the ground is poor
current will be high enough to overcome that resistance, which could be high
enough to damage the transistor.
> How do you think the connection to
> ground is made? It is done through some kind of driver that involves a
> solid state device, such as a transistor. Changing the coil resistance
> changes the current through the driver by changing the total impedance of
> the loop.
Read above statement.
Ford has never called it an emission part. If you were to look up in the
emission warranty parts list, it is not in there.
I don't understand why Ford used this device as well. Only
Taurus/Sable/Continental and the last few model years of Tempo/Topaz used
it. Everything else worked just fine with stand alone relays.
>Either that or they exploited federal regulations
> imposed on their previous set up. Either way, by making it such a big
deal
> and completely mysterious they've got almost guaranteed control.
>
> I think that the relays aren't a big deal because relays are not very
> different when within the same rating range. The diodes across the relays
> are good to have. I don't know why some have them and some don't.
Perhaps
That is evolution. EEC3 had very little diode protection.
> the circuits that don't have them can take a voltage spike, maybe they
> aren't digitally (or should I say microprocessor) controlled circuits.
Now
> the question is, what about this other support circuitry? Is it for
timing?
> Is it for current limiting? Could be. Let's do more research.
>
That would be a good question, the models that do not use the "black box" do
not have all the supporting circuitry. I suspect some vendor made a killing.
> I am part yahoo and part conservative myself. I think "no user
> serviceable parts" usually depends on the user, yet I tend to read the
> manual when available. The manual doesn't really say what's in these. I
> was hoping to get some answers on that from here myself. Well I've gotten
> some, but maybe it's time to get out the hacksaw (or is there a better way
> to get into these units).
Just drill out the two rivets at the corners. Depending on year you will
either have Siemens relays or Bosch. Four in all. One power resister about
(62 ohms) The rest is just capacitors, resisters and what looks like could
be transistors or voltage regulators ( I haven't taken the time to look up
the numbers )
> If any of you guys that have ripped these apart
Thomas H. Moats
news:lLLj9.10332$XE1.9...@newsread2.prod.itd.earthlink.net...
> going back through the driver. When a coil is energized it creates a
> magnetic field. When the power is disconnected the field decays. The
> changing field (change in flux density, I believe - yes magnetic flux is a
> real thing, I didn't say flux capacitor) creates current in the coil, just
> like moving a magnet trough a coil. Many ignition coils work this way
> (field decay type rather than capacitive discharge). You can get a lot of
> voltage out of a rely or any inductive load. These high voltages are
> troublesome to microprocessors and their CMOS technology friends, among
> other semiconductor devices.
>
That is why Ford has so many diodes in the harness as well as in coil wound
parts now.
> Someone said that the relay coil circuit is completed by the EEC
> connecting the coil to ground. They said that this meant that the coil
> resistance didn't really matter. That isn't really true. The resistance
in
> the coil effects the amount of current flowing through the circuit between
> the power source and return (ground).
Current will only go as high as needed to over come the load. The resistance
of the coil is the primary load, after the load ( ground ) current will only
be high enough to go to ground. The only real resistance in the circuit that
matters after the load is ground after the transistor. If the ground is poor
current will be high enough to overcome that resistance, which could be high
enough to damage the transistor.
> How do you think the connection to
> ground is made? It is done through some kind of driver that involves a
> solid state device, such as a transistor. Changing the coil resistance
> changes the current through the driver by changing the total impedance of
> the loop.
Read above statement.
Ford has never called it an emission part. If you were to look up in the
emission warranty parts list, it is not in there.
I don't understand why Ford used this device as well. Only
Taurus/Sable/Continental and the last few model years of Tempo/Topaz used
it. Everything else worked just fine with stand alone relays.
>Either that or they exploited federal regulations
> imposed on their previous set up. Either way, by making it such a big
deal
> and completely mysterious they've got almost guaranteed control.
>
> I think that the relays aren't a big deal because relays are not very
> different when within the same rating range. The diodes across the relays
> are good to have. I don't know why some have them and some don't.
Perhaps
That is evolution. EEC3 had very little diode protection.
> the circuits that don't have them can take a voltage spike, maybe they
> aren't digitally (or should I say microprocessor) controlled circuits.
Now
> the question is, what about this other support circuitry? Is it for
timing?
> Is it for current limiting? Could be. Let's do more research.
>
That would be a good question, the models that do not use the "black box" do
not have all the supporting circuitry. I suspect some vendor made a killing.
> I am part yahoo and part conservative myself. I think "no user
> serviceable parts" usually depends on the user, yet I tend to read the
> manual when available. The manual doesn't really say what's in these. I
> was hoping to get some answers on that from here myself. Well I've gotten
> some, but maybe it's time to get out the hacksaw (or is there a better way
> to get into these units).
Just drill out the two rivets at the corners. Depending on year you will
either have Siemens relays or Bosch. Four in all. One power resister about
(62 ohms) The rest is just capacitors, resisters and what looks like could
be transistors or voltage regulators ( I haven't taken the time to look up
the numbers )
> If any of you guys that have ripped these apart
> have good pictures let me see them.
Take a look. This is from an 89 Sable. The relay for the fuel pump is open.
I have not found any other problem with it.
>
> Does anyone in the CT area have some of these that are working and
opened
> or any unopened that they're willing to possibly destroy by opening and
> would like to help further the research? Let me know. I would like to
> analyze a few myself. I have a lot of applicable experience. I think the
> group is hungry to know the truth about these and I think there's only one
> way to find out for sure. We can put our experience together and get the
> answers.
>
> I wonder what the compatibility software junk yards use has to say about
> these. I'm not going to just say these things are compatible, that would
be
> irresponsible, but I bet a lot of them are, regardless of what Ford says.
> They have their own interests, we have ours. No one seems to be a pro on
th
> ese, so post what you know and eventually we'll figure it all out.
>
>
>
----------------------------------------------------------------------------
----
BOB URZ
"Thomas H. Moats" wrote:
>
> Current will only go as high as needed to over come the load. The resistance
> of the coil is the primary load, after the load ( ground ) current will only
> be high enough to go to ground. The only real resistance in the circuit that
> matters after the load is ground after the transistor. If the ground is poor
> current will be high enough to overcome that resistance, which could be high
> enough to damage the transistor.
>
Well, i have basically agreed to all you have said up to this point.
Until this. If you look at a relay circuit, its basically a series circuit.
12 volts DC is the source. The transistor driver is in series with the relay
coil.
When the transistor is activated, the same current flows from collector to the
emitter through the relay oil to ground. (not counting the minuscule base drive
current)
Circuit completed. relay activated. current flows. Now, if you had a bad
ground n the circuit, that would ADD resistance to the series circuit. Adding
resistance to a series circuit would REDUCE the current flow, and possibly
cause the relay NOT to engage due to a LACK of current flow. Adding more
resistance to the series circuit would not cause the circuit
to draw more current, it would draw less.
The only thing that would cause the transistor to draw MORE current would be
a short to ground between the transistor and coil, or a coil that was damaged
and has shorted coil windings which could lower its DC resistance.
Or, possibly a shorted snubbing diode across the coil.
I agree that there should be some interchange between some of these modules.
The question is what years of what modules of cars. Adding the snubbing diodes
to the relay coils should just be an improvement in the modules. Not a reason
why they won't swap. Now, a pin change of function inside the module is a
GOOD reason why they don't swap.
I have a few spares laying around myself off of a few taurus. How hard is it to
pry one
open? That's one thing i have not tried yet myself. Can you put the cover back
on it when you pry it off?
BOB
Stan Kasperski
the AC clutch was not functioning. If I remember correctly, the relay involved
was a solid state device. In any case, I was not about to spend well over $100
to replace one bad relay out of 4. I went to Radio Shack, bought a 12 V relay
for about $4 and rewired the connector to bypass the internal SS relay and
activate the external RS mechanical one. It worked fine for the 2-3 years I had
it subsequent to the "fix".
Stan K.