E30 Erratic Temp Gauge now Dead
camp
pegged "HOT" until the engine (or cabin??) warms up a bit --- then it
will work well.
Now, after some (unrelated?) rutting around in the center dash to
replace the OBC display lamps, the TEMP guage has failed completely.
The Service Interval LEDs, TACH, and MPG meter have been D.O.A. for
more than a decade --- with no ill effect on TEMP readings. This TEMP
gauge problem is a new problem.
Shorting the sender wire on the engine block changes nothing.
Any ideas where else to look?
TIA
Mark Mentovai
For the water temperature gauge, pull the cluster and check (tighten)
the ground nut on the back of the gauge.
For the tachometer, service interval indicator, and "energy control,"
the problem is probably the service interval board or its batteries.
The board is inside the instrument cluster, so you might as well
check/fix/replace it while you're fixing the temperature gauge. There's
lots of information available on the web that describes gauge problems
and how to fix them, look for e30 "si board".
Mark
1987 BMW 325 (E30), 87kmi, sold yesterday :(
1996 BMW 328is (E36), 79kmi
camp
TACH/MPG are still dead.
I haven't reset the SI lights yet. Is there a definitive test for a
bad SI board --- or have I just performed it by replacing the
batteries?
BTW - The TEMP gauge is back and working fine. Thanks!
I also reflowed some solder.
TIA
Mark Mentovai
> After replacing the SI batteries (adding a 3-wire remote box) the
> TACH/MPG are still dead.
>
> I haven't reset the SI lights yet.
If you have no SI lights, a reset won't help.
> Is there a definitive test for a
> bad SI board --- or have I just performed it by replacing the
> batteries?
If the SI lights are all out and the tachometer and "energy control"
aren't working, and replacing the batteries didn't do anything, the SI
board is dead (or not getting power).
> BTW - The TEMP gauge is back and working fine. Thanks!
> I also reflowed some solder.
Excellent!
Mark
camp
Yes, I *do* have SI lights. The SI board is getting power.
The old SI batteries were so dead that the LED's were displaying
"Yellow & Red w/no 'Service' Light" --- even when the ignition was
switched off.
With the new batteries, things have improved considerably. I now have
"Five green LEDs plus the 'Service' light illuminated". All lights now
switch On & Off properly with the ignition.
I have not performed an SI Reset and the TEMP/MPG gauge is still dead.
I should mention that I replaced the first set of SI batteries six
years ago and could never get the SI lights to do a proper reset, and
could never get the TEMP/MPG to work.
So getting back to my original question ... if I have a fresh set of
charged NiCads plus power getting to the SI board, is there anything
else I can do to get the TACH/MPG working again?
And is there any definitive test to tell if the TACH/MPG problem is
with the SI board, the Instrument cluster PC board, or with the
TACH/MPG gauge itself?
Thanks (again) in advance!
Mark Mentovai
> With the new batteries, things have improved considerably. I now have
> "Five green LEDs plus the 'Service' light illuminated". All lights now
> switch On & Off properly with the ignition.
You should never see any green LED lit with the OILSERVICE or INSPECTION
inscription. It's not "no lights," but it's still broken.
> I have not performed an SI Reset and the TEMP/MPG gauge is still dead.
Try a reset, it's cheap (free) and easy. I bet it won't change
anything, but it can't hurt, and if it surprises you and actually brings
the lights and gauges into compliance, you'll be thrilled.
> I should mention that I replaced the first set of SI batteries six
> years ago and could never get the SI lights to do a proper reset, and
> could never get the TEMP/MPG to work.
Yet another reason to suspect that the SI board is gone.
> So getting back to my original question ... if I have a fresh set of
> charged NiCads plus power getting to the SI board, is there anything
> else I can do to get the TACH/MPG working again?
You said you reflowed some joints. Did you do any on the SI board?
Since you're apparently handy with an iron, you might give this a try.
(Depending on the results of a visual inspection, I sure would.)
Other than that, really nothing beyond a new SI board would get those
needles moving, unless it turns out to be the gauge. But since your SI
board sounds flaky anyway (won't reset), I'd strongly suspect it.
Multiple failures aren't out of the question, but I'll see if I can get
Murphy's Law suspended this week.
> And is there any definitive test to tell if the TACH/MPG problem is
> with the SI board, the Instrument cluster PC board, or with the
> TACH/MPG gauge itself?
Not really without spares. You could look at the outputs from the SI
board to the gauges, but I don't know if you'd be looking for straight
analog voltage or what.
I don't think E30 clusters or gauges go for too much on a certain online
auction site that shall remain nameless, if you'd like to try swapping
parts. If you want to do this, get a cluster from the proper
manufacturer (VDO or BoschMotoMeter) and same model and similar year (SI
lights changed in 1986 or 1987) to maximize interchangeability.
My money's on the SI board. The only three functions it's responsible
for have failed. Of course, I understand your hesitation, because it's
not my money at stake here but your own.
Mark
camp
So ... reseting the lights (through a 470k resistor) only made things
worse. The green lights are still illuminaated and the formerly steady
INSPECTION light is now flashing.
While I rummage through a drawer for some black electrical tape to
cover the display ... does anyone know what "flashing" signifies on a
properly funtioning SI board?
The flashes are far too regular to be simply the result of the board
failure alone. They must be a programed indication for something --
perhaps they're flashing "Buy-a-new-SI-board" in German.
Mark Mentovai
> While I rummage through a drawer for some black electrical tape to
> cover the display ... does anyone know what "flashing" signifies on a
> properly funtioning SI board?
Properly functioning SI boards don't flash.
> The flashes are far too regular to be simply the result of the board
> failure alone. They must be a programed indication for something --
> perhaps they're flashing "Buy-a-new-SI-board" in German.
It doesn't need to mean something, it could just be triggered by a
dependable (but unintended) charge-discharge cycle of a capacitor.
gmfe
Is there any sign of leakage from the batteries on the board - and - if
there is any damage to the board traces by the edge where there are two
indentations.
Battery leakage is fairly common and you may have not noticed it. I
think you mentioned your Indicator lights were on even when the ignition
was off? If so, that is a typical battery leakage sign.
The damage on the edge of the board is caused by replacing the cluster
and using the longer screws at the bottom rather than where they
belong - at the top. They are long enough to reach the SI Board and
create two damaged areas, effecting at least one trace and possibly two.
You can solder a jumper wire (or wires) to fix the "long screw" problem.
Good Luck!
"Mark Mentovai" <www.mentovai.com-slash-contact.html@_._> wrote in
message
news:www.mentovai.com-slash-conta...@news.isp.nyc.eggn.net...
Jim
* Temp gauge flickers all the time--holds at the middle, but flickers
every few seconds.
* MPG gauge is dead.
* TACH is pretty much dead.
* "Inspection" light comes on and is not-resettable.
Currently I'm running without batteries on my SI board, and am not
convinced that replacing them will fix my three gauges. And after
reading the text from the original poster "camp", I am even more
convinced that the problem is not related to the batteries. Although
I do realize our gauges and SI board are different, but I'm sure the
problem(s) are somewhat related.
I had removed my batteries months ago becz my SI inspections lights
(greens, yellow, and red) were coming on and were not resetable.
I'm sure the batteries' sole purpose is to keep track of mileage when
the car 12V battery is removed. I.e., they just keep some on-board
memory (RAM of some sort) refreshed.
I guess, as most folk would agree though, the problem still lies with
the SI board. Probably not the batteries, but maybe a faulty
component. Diodes in general fail more often than transistors and
resisters. Maybe a burnt capacitor?
I am hoping, however, that someone out there has the answer. I have
found these newsgroups very helpful, and the web has tones of stuff on
SI boards and batteries, but so far, have not found a definitive
answer. I really don't want to start inspecting components on a
circuit board, and have no intensions of buying a used SI board, as
the same problem will probably occur. My guess is that it's a bad
ground or power wire/trace,,,I say this becz my gauges are not always
completely dead--sometimes they flicker or move a little.
Best of luck to the original poster with the '86 325e,,,and if anybody
has more info or tips, they'd be much appreciated.
__
James.
gmfe
You can use Radio Shack, or similar, for replacements.
While it's out of the cluster, also do an inspection of the SI board for
any damaged traces, loose solder, etc. Also, check the main board for
the same.
On the Temp gauge, make sure the washer and nut on the back of the
cluster are installed (and tight) and are not corroded. Also, check the
coolant temp sending unit.
If you install new batteries (you must have batteries installed for the
gauges to work correctly), re-solder any suspicious areas, jump any
broken traces, and clean all the connections (speedometer, tach, temp,
etc.) with electronic cleaner, you may have a fully working instrument
cluster.
Good Luck!
"Jim" <jgurne...@hotmail.com> wrote in message
news:8ac9a372.04053...@posting.google.com...
Richard Sexton
gmfe <gm...@hotmail.com> wrote:
>You may want to re-consider installing new batteries in your SI Board.
>You can use Radio Shack, or similar, for replacements.
Do they have to be NiCad or can they be NiMH? No guesses
now, has anybody tried this?
--
Usenet special: on cases of any filters for BMW: http://u.bmwz.org
http://www.mbz.org | Mailing lists: http://lists.mbz.org
633CSi 250SE/C 300SD | Orkut:RS79 Classifieds: http://ads.mbz.org
2 X 280SE 350SLC | Watches list: http://watches.list.mbz.org
Somebody
"Richard Sexton" <ric...@vrx.news> wrote in message
news:HyMzL...@T-FCN.Net...
> In article <ilVuc.33320$zO3....@newsread2.news.atl.earthlink.net>,
> gmfe <gm...@hotmail.com> wrote:
> >You may want to re-consider installing new batteries in your SI Board.
> >You can use Radio Shack, or similar, for replacements.
>
> Do they have to be NiCad or can they be NiMH? No guesses
> now, has anybody tried this?
Since NiMH batteries are not compatible with NiCad chargers and vice versa,
I would definately NOT try that.
-Russ.
gmfe
"Somebody" <some...@nospam.russdoucet.com> wrote in message
news:4e3vc.5$vO1...@nnrp1.uunet.ca...
camp
learned a lot ... But the SI board is still dead.
I agree with Jim that there is no definitive answer (in English) on the
web.
The TEMP gauge was fixed by cleaning black dust/corrosion on the trace
where the TEMP's threaded mounting stud contacts the printed circuit
board.
In all my reading, I have never found any mention of a faulty
electronic component on the SI board. Every fix I've found on the web
relates to [1] changing the NiCad (later Lithium) batteries, [2]
cleaning battery leakage, [3] reflowing solder joints, [4] checking for
bad traces, [5] checking for dash trim mounting-screw damage, and [6]
checking for dirty guage connecting pins.
I have tried all six suggestions. The SI board is still dead.
Having tried everything else, I am forced to suspect a bad electronic
component on the SI board.
Nevertheless, the preponderance of web evidence seemns to indicate that
it is NOT a bad electronic component (simply by virtue of the vast
numbers of boards successfully repaired by other more mechanical
methods).
The only thing I can imagine is that component-level failures, if they
exist, are fixed by "replacing the board" and we web gurus discount
those "replacement" successes, chalking them up to guys "too lazy to
solder in new batteries".
I sure wish I read German -- it's the only idea I have left.
Camp
In article <yE3vc.7155$Yd3....@newsread3.news.atl.earthlink.net>, gmfe
Yan Stambouli
Try replacing the electrolytic capacitors. They actually get dry inside and
lose much of their properties.
Make sure to get your polarity right.
Secondly, when replacing NiCads, you must precharge them before installation
on the board. This is not the case for the Primary Lithium-Ion batteries,
which are not rechargeable.
Also the ribbon cable solder joints are also worth reflowing, even if they
seem good.. Depending on your location, temperature variations move the
sleeve enough to weaken them over time. Vibrations can't help either.
Enjoy
Yan 86 735i
camp
> I have revived a few boards doing the following:
> Try replacing the electrolytic capacitors. They actually get dry inside and
> lose much of their properties.
No kidding!!?? The caps? That's an easy fix. I'll definitely try
that.
Since the SI board is not a mission-critical repair, I've made this my
"personal best" goal to repair rather than replace, and yours is the
first mention I've encountered of a true board-level repair.
(This SI board actually died quite a number of years ago, so whatever
component failed back then probably wasn't from age ... but if
replacing the caps has worked for you, I'll take a shot at it.)
> Secondly, when replacing NiCads, you must precharge them before installation
> on the board.
Yup. I did that. Running an external AA box, too.
> Also the ribbon cable solder joints are also worth reflowing, even if they
> seem good.
What ribbon cable? Are we talking the same thing? I've seen mention
of ribbon cable on a 6-series, but I've only found 24-pin Amp
connectors on this E-30 VDO OEM'd cluster.
TIA
Racer
now all fine