Adding a Garmin to a 1984 MBZ 240D

[Loony]

Hello again Experts,

Many years ago just after I bought that MBZ I decided to dump the
cigarette lighter and I wasn't sorry about that.
Now, that old car is still running extremely well, and I am now trying
to connect my Garmin to the empty cigarette lighter spot.

I was able to pull out the complete cigarette lighter and was surprised
that I could see no electrical connection. Years ago I installed a radio
just above that and I am not sure if I hid the lighter wire in the radio
compartment.

I put the complete cigarette lighter back in its place and then I pushed
the Garmin GTM26 down into it. I looked for a connection to test whether
it was live but then I ran out of time. I can't even remember how I
installed the radio. I guess I could still pull buttons until I get the
radio out.

Any suggestions appreciated.

Thanks.

[Roland Franzius]

Originally the radio is connected to the cigarette lighter with a red
wire in the middle console fused with a glas cylinder fuse.

The lighter is connected with I+II of the ignition key. Radio is off in
key position 0.

Most W123 cars use instead an extra wire to battery plus for radio use
independent of ignition.

--

Roland Franzius

[Loony]

Thank you Roland.

I managed to get the radio pulled out and I was shocked at the numbers
of wires. The ash tray has no electric connection now, so I need to find
and install the part that will provide the "juice" to the Garmin.
Will look for that red wire and fuse.

[tra...@optonline.net]

> Will look for that red wire and fuse.- Hide quoted text -
>
> - Show quoted text -

I added extra cigarette lighter type sockets on both sides
of the tranny hump just below the radio area in my 300SD.
They are available at autoparts supply houses. One
reason I did that was a plug from something would not
clear the ashtray opening. Having extras is convenient
for charging cell phones, iPod, etc.

[Loony]

That is interesting Trader4.

One connection is all I need - the one for the Garmin.
I pulled the radio out and looked for loose wires. I found 3 of them.
One had a 1/4" wide slot for some spade connection. According to
page 82-909 of the MBZ Manuals, the spade is a connection for the
radio. But the radio is working already without it.

The other two unused grey wires have the same size sockets (about 3mm
diameter) at the ends. Both ends were covered with rubber caps. One of
the contacts has a red color and the other has a cream color.

Looking forward in the seat and up under the ash tray, on the left side,
there are three holes with possible contacts but none of the three
possible contacts can be used.

When I have some more time I'll try my multimeter on the contacts to
try to find a suitable connection for the cigar + Garmin connection.

Suggestions please.

THX.

[Loony]

Second thought: The spade connection is very likely to be negative,
since the car body is positive. I could trim that contact to a spade
like shape and it may fit one of the 2 slots just under where the cigar
lighter was, or my Garmin plug, is now.

[tra...@optonline.net]

> lighter was, or my Garmin plug, is now.- Hide quoted text -

>
> - Show quoted text -

When you figure out what wire to tap into, I'd consider:

A - Do you want it on all the time or only when the key is
on

B - Find out what fuse the proposed wire uses. If you're
using it for just a Garmin, etc, probably doesn't make much
difference. But if you're hooking up a real cigarette lighter that
could be used for that, you want circuit that has a
decent size fuse.

[Tiger]

Use a voltmeter and you will know what you want to do. Highly recommended
you use switched positive... so Garmin shuts off when you shuts off the car.

[Loony]

Only when the key is on.

> B - Find out what fuse the proposed wire uses. If you're
> using it for just a Garmin, etc, probably doesn't make much
> difference.

Only for Garmin.

But if you're hooking up a real cigarette lighter that
> could be used for that, you want circuit that has a
> decent size fuse.

My car never had the smell of smoke. I dumped the part that
was used to do the actual cigar lighting, as soon as I took
the car from the docks.

Thanks Trader4.

[Loony]

Hello again Tiger.

Hmmm, switched positive? We would want the contact to break when the
ignition key was open (or off?). Isn't the chassis positive? With an
Ohmmeter I should be able to tell whether that spade connection is
positive or negative. Will let you know then.

Thanks for your interest

[Loony]

Back again Tiger and Trader4.

Thanks Tiger for the correction. Was there a time in the past when the
positive on the battery was connected to the chassis? It has been a
while since I had to deal with this before, so I am out of touch.

I left my ignition key at zero and setup a lead between the + on the
battery and the area with the radio. I really was surprised that all 3
connections the red, white, and spade were positive. The red and white
had 2 contact points - a metal collar and a hole in the middle for
another contact. Both contact points, outer and inner, on the red and
white were positive.

It looks like I have to find another connection for the Garmin :-(
I haven't tried with the ignition key on yet. Any possibility there?

Have a great weekend :-)

[tra...@optonline.net]

On Feb 4, 8:14 am, Loony <Lo...@nowhere.con> wrote:
> On 03/02/2012 19:34, Loony wrote:
>
> > On 01/02/2012 20:46, Tiger wrote:
> >> Use a voltmeter and you will know what you want to do. Highly
> >> recommended you use switched positive... so Garmin shuts off when you
> >> shuts off the car.
>
> > Hello again Tiger.
>
> > Hmmm, switched positive? We would want the contact to break when the
> > ignition key was open (or off?). Isn't the chassis positive? With an
> > Ohmmeter I should be able to tell whether that spade connection is
> > positive or negative.

A voltmeter will tell you polarity. An ohmmeter, or a VOM
set in resistance measuring mode, ie ohm mode, should never be
connected to a live circuit. You also want to
make sure that if the meter has terminals for measuring
AMPS, you know what you're doing when you connect
the test leads to those or you'll blow the meter or meter
fuse.

Will let you know then.
>
> > Thanks for your interest
>
> Back again Tiger and Trader4.
>
> Thanks Tiger for the correction. Was there a time in the past when the
> positive on the battery was connected to the chassis?

I think through history there were some
cars made around the world that used positive ground.
But that was a long time ago and in the world today of
the cars on the road, 99.99% are negative ground.

It has been a
> while since I had to deal with this before, so I am out of touch.
>
> I left my ignition key at zero and setup a lead between the + on the
> battery and the area with the radio. I really was surprised that all 3
> connections the red, white, and spade were positive. The red and white
> had 2 contact points - a metal collar and a hole in the middle for
> another contact. Both contact points, outer and inner, on the red and
> white were positive.

You want to GROUND the negative lead from the meter
to metal on the chassis and touch the positive lead from
the meter to the wire in question.
The way you're testing, you're finding circutis that are
NOT energized but have some load on them. For
example, I could do it your way and touch the horn
circuit and it would show voltage.

For this type of work,
a 12V test light that is essentially a bulb in a holder with
a pointed end and a wire you can connect to ground is
easier to use. You can buy them at any auto supply
store for a few bucks....

Google "12 volt test light"

[Loony]

I placed the ignition key at the first stop and then measured the above
resistances. They were exactly the same as in the above effort. Now I
have to search for that negative connection.

On the other hand, my speakers developed cracks in the speaker
diaphragms, so I could temporarily take the connection that was intended
for the lighter and use that for Garmin, but I would then
have no speaking voice to guide me. Waaaaahhhh!!! Is there no end?

The speakers had only two screws to mount to the dashboard, so the
vibrations did the damage. The diaphragms have several concentric
sections (annuli or, less used, annuluses, I believed they are called)
in the diaphragms. One of those annuli cracked up on each speaker. They
still made reasonable sounds though. I might be able to find a third
screw position on each speaker and then try to seal up the cracks.
Anyone know of a material to replace the cracked annuli? What is there
already seems to me to be some kind of tough paper.

Wish you a happy week ahead :-)

[tra...@optonline.net]

You should NOT be measuring resistances on a live
circuit. You are looking for 12 VOLTS and should be
measuring VOLTAGE.

> Now I
> have to search for that negative connection.
>
> On the other hand, my speakers developed cracks in the speaker
> diaphragms, so I could temporarily take the connection that was intended
> for the lighter and use that for Garmin, but I would then
> have no speaking voice to guide me.  Waaaaahhhh!!! Is there no end?
>
> The speakers had only two screws to mount to the dashboard, so the
> vibrations did the damage. The diaphragms have several concentric
> sections (annuli or, less used, annuluses, I believed they are called)
> in the diaphragms. One of those annuli cracked up on each speaker. They
> still made reasonable sounds though. I might be able to find a third
> screw position on each speaker and then try to seal up the cracks.
> Anyone know of a material to replace the cracked annuli? What is there
> already seems to me to be some kind of tough paper.
>

> Wish you a happy week ahead :-)- Hide quoted text -

>
> - Show quoted text -

Are you sure it cracked due to mounting? How old are
they? The cracked ones I've seen have been because
they were old, dried out and brittle from long term exposure
to heat inside the car.

[Tiger]

Majority of the cars in the world is ground chassis. Very rare old old cars
had positive ground.

If your radio does not turn on when the ignition is off, you have a switched
positive. It is the red wire from the radio.

[Loony]

Thanks Tiger.

When the ignition is off the radio is off on mine. Yes, there is a red
wire (actually a red plug) that is free. I took the ashtray out of its
cubby hole and then I noticed a small (springy) lump of copper sticking
out of the left side of the tray (looking forward in the car). There is
another built-in contact to the left of the ashtray for contact with
that copper lump. That seems to be the contact that would close the
circuit through the cigar lighter or the Garmin cable now.

The red plug needs some kind of adapter to keep contact with the tray.

Suggestions please.

[tra...@optonline.net]

I don't have one here to look at. But you are on the
right track. As I recall in my 300SD they use a sweeping
contact on the left side of the ashtray that makes contact
with the ashtray holder that is fixed in the console. On
the back of the ashtray holder there must be some form
of connector, wire, etc that gets hooked up to 12 volts.
You need to find out what that connector on the back of
the ashtray holder is vs the connector on the red wire.
My first suspicion would be that they are designed for
each other. If not, all you need to do is figure out what
the connecting means is on the ashtray holder and how
to attach to it.

[Tiger]

Just bend whatever you need to do to get it to contact.

As for hardwiring, use the scotch-splice... no need to cut at all.

As for the radio... you do have switched positive... cigarette lighter is
also switched positive... Look at your radio harness... the red wire from
the radio is for switched positive... from factory wiring, it can be any
color... just splice the wire from this position and you are okay with the
GPS. Just make sure you got the positive wire right on the GPS.

[Loony]

Thanks again Trader4 and Tiger.

I looked hard at the area where that copper lump in the left side of the
tray was supposed to complete the circuit to the lighter but I doubt
that now. What is it for then?

I can't see any way to connect that red wire to the base of the cigar
lighter. At that base there are two contacts and I would need some
device that could connect that red plug to those two contacts.

My MBZ manual (series 123, Vol 2, page 82-909) shows the way to set up
the radio and the lighter but it seems that the bums who installed the
radio mucked it up.

[tra...@optonline.net]

On Feb 7, 5:59 am, Loony <Lo...@nowhere.con> wrote:
> On 07/02/2012 04:42, Tiger wrote:
>
> > Just bend whatever you need to do to get it to contact.
>
> > As for hardwiring, use the scotch-splice... no need to cut at all.
>
> > As for the radio... you do have switched positive... cigarette lighter
> > is also switched positive... Look at your radio harness... the red wire
> > from the radio is for switched positive... from factory wiring, it can
> > be any color... just splice the wire from this position and you are okay
> > with the GPS. Just make sure you got the positive wire right on the GPS.
>
> Thanks again Trader4 and Tiger.
>
> I looked hard at the area where that copper lump in the left side of the
> tray was supposed to complete the circuit to the lighter but I doubt
> that now. What is it for then?

I just pulled out the ASHTRAY on my 80 300SD. It has
a copper springy contact, about 1/4" square on the left
side. Just below that is a smaller round button, looks
like brass, about 1/8" in diameter. Those make contact
with the left side of the ASHTRAY HOLDER that is
fastened in the car. As you open or close the ashtray,
they remain in contact with the corresponding contacts
on the ashtray holder.

Now I don't have an ashtray holder and don't know
what exactly is behind it. But clearly on the holder
from the point on the left side where the wiping contacts
make contact, there has to be a 12V and ground lead
wire or connection. With the holder and tray in front of you
it should be easy to trace.

>
> I can't see any way to connect that red wire to the base of the cigar
> lighter. At that base there are two contacts and I would need some
> device that could connect that red plug to those two contacts.

What kind of contacts? Spade? That would make sense.
If they are, this is the female spade type connector:

http://www.autoparts2020.com/rsdev/part_group.jsp?PHPRJ_GROUP_ID=47410&cat=2,3,4,5,9

[Loony]

Thanks Trader4.

You hit the nail right on the head.

I was a bit fed up with the job until today. Previously I brought an
insulated wire from the car battery+ out of the engine compartment and
back into the car. At one point a contact I made near the lighter ended
up with the insulation on the wire dripping off every few inches. I got
out in a hurry.

Today I had a cable with thicker insulation and I placed a board under
the wire where it crossed the engine. I then made some measurements and
I found the negative connection near where that copper bulge would
contact. It seems to be ok, so now all I need is a short piece of wire
about 6" with a spade connection at each end. The free female spade
connection from behind the radio takes one end of the short wire and the
spade connection at the other end of that wire makes contact at a female
spade connection right under where the cigar lighter was at one time.

Now I have to go on Safari to find the missing spades :-)

[Tiger]

If you bring a positive from battery to inside the car, it must be fused
within 6" at the battery. This is your safety factor in case if your wire
ever get shorted. Otherwise, you have an extremely high risk of car fire as
you experienced the precursor to car fire... the insulation melting off.

At the same time, when you do this, you are providing 100% power all the
time to your GPS... which will not allow the GPS to turn off automatically
when power disappear. So, you will drain your battery power and if you got
an old battery, soon, you will not be able to start your car up.

Do yourself a favor at this time, let someone who knows about electricity
install it for you. You are risking car fire and problems down the road at
this point.

[Loony]

Thanks again Tiger.

On 12/02/2012 05:03, Tiger wrote:
> If you bring a positive from battery to inside the car, it must be fused
> within 6" at the battery. This is your safety factor in case if your
> wire ever get shorted. Otherwise, you have an extremely high risk of car
> fire as you experienced the precursor to car fire... the insulation
> melting off.

That is a good point. I'll have to get a wire with a fuse. Remember that
mine is a diesel car and does not have the hazards of gasoline.

> At the same time, when you do this, you are providing 100% power all the
> time to your GPS... which will not allow the GPS to turn off
> automatically when power disappear. So, you will drain your battery
> power and if you got an old battery, soon, you will not be able to start
> your car up.

I don't think so. Using that battery+ connection wire was only to find
the contact point of the copper bulge in the ash tray. I did find it and
I am not using that wire any more.

The Garmin and the radio shut off with the ignition key.

The GPS is not even installed yet. It seems that the wire with the red
plug was intended for the cigar lighter and the female spade connection
for the radio. But the radio is already connected. It and Garmin shut
off when the ignition key goes to the off position and the drain of the
Garmin is not likely to be as strong as that of the radio.

It appears that I have now to complete the job by getting a wire about
6" to 12" long and with soldering small "spades" at the ends of the
wire. That should not be too difficult.

> Do yourself a favor at this time, let someone who knows about
> electricity install it for you. You are risking car fire and problems
> down the road at this point.

I have done wiring and rewiring in a number of areas in that car and
previous cars and I have had no bonfire yet. I have already called many
service garages in my area and told them about the problem. Not one was
interested and none had any experience of satellite devices. I'll have
to try the MBZ HQ for more info.

Hope you had an enjoyable weekend :-)

[Tiger]

Sounds like you do have some experience and still learning. Even though
there is no gas fuel, the car itself is quite flammable.

You don't want to contact garage or mechanics... they are not electronic
wizard. You want to talk to car stereo guys.

[Loony]

Hello Tiger and other great helpers :-)

I have made a little more progress. The Garmin is now in its place but
the cable is 5' long. Seems that I need to exchange it for a 30" one
instead. I made up a cable with two male spade connectors and they seem
to work very nicely with the radio connection and the Garmin. I have not
yet made a final test on the Garmin cable.

I'm curious about how the Garmin cable connects to the Garmin. It seems
to have a metal band running around the end at the Garmin. How can two
contacts work like that? Looking inside that band seems to be a black
something or other. The Garmin is connected to the windshield, so it
can't be grounded.

I have a small - about 9"x4"x4" speaker and I want to set it up
temporarily - I like very much listening to the Garmin. I pulled two
speaker cables from one end of the dashboard to connect to the Altec
Lansing. The dash connection is one black wire and the other a black
with a blue stripe. The Altec has a one black wire and the other is
black but with a red band near the end. Should the dash black and the
Altec black be connected? If yes, then I guess the black with the blue
should connect with the black with the red.

Help please.

TIA

[Tiger]

First of all... Most new Garmin are now only 5 volt appliance because they
adopted the USB connection. The cigarette lighter adapter has a voltage
regulator built in that reduce the voltage from car 12 volt to usable 5 volt
for the Garmin.

If you simply just cut off the cigarette lighter, you have cut out the
regulator and will send 12 volt directly to the Garmin... thereby fry your
GPS instantly.


As for the speakers, you cannot connect from Garmin directly to speaker...
it does not work. The signal from Garmin headphone jack needs to be
amplified into car stereo... so it is usually connected to the aux input for
your car stereo if you have one... Most aux input is RCA type so you will
need from 2.5mm headphone jack to RCA L/R cable... common and sold at Radio
Shack.

I still think you should take it over to stereo shop and let them do it for
you.

[Loony]

Thank you Tiger,

On 16/02/2012 17:03, Tiger wrote:
> First of all... Most new Garmin are now only 5 volt appliance because
> they adopted the USB connection. The cigarette lighter adapter has a
> voltage regulator built in that reduce the voltage from car 12 volt to
> usable 5 volt for the Garmin.

Interesting information there.

> If you simply just cut off the cigarette lighter, you have cut out the
> regulator and will send 12 volt directly to the Garmin... thereby fry
> your GPS instantly.

I have no intention of cutting off the cigarette lighter. I made up a
cable with two spades and one is connected to the cable from the radio
and the other is connected right under where the cigar lighter would be.
I connected a very long Garmin GTM 26 cable, 5' long, and it looks like
a mess. I'll have to return it to the store and exchange for one about
30". However, I connected the long cable both to the Garmin and to the
cigar lighter. So, at least my Garmin wasn't blown up. I haven't tried
taking the voltage from the Garmin cable where it is connected to the
Garmin, because I didn't know to measure it there? I saw only one
contact at that end.

> As for the speakers, you cannot connect from Garmin directly to
> speaker... it does not work. The signal from Garmin headphone jack needs
> to be amplified into car stereo... so it is usually connected to the aux
> input for your car stereo if you have one... Most aux input is RCA type
> so you will need from 2.5mm headphone jack to RCA L/R cable... common
> and sold at Radio Shack.

If the aux input needs to be connected to the radio, then the only
vacant connections behind the radio are the two we talked about
previously. They are the two vacant plugs - one cream and the other red.
So the aux input from the Garmin should connect to one of those two. If
there is only one connection, should it be red or white? I'm
pretty sure that I have those RCA connections. Thanks again Tiger :-)

I had no intention of connecting Garmin to the speaker. I was taking the
cables from where the old speaker was previously connected and surely
those cables came from the radio. For a temporary connection I wanted to
use them on the Altec Lansing speaker, at least for my radio and I was
hoping I could connect the Garmin too. Better still if the Garmin can
make its own sounds. Just curious, should Garmin not have that extra cable?

> I still think you should take it over to stereo shop and let them do it
> for you.

I'll have another shot at this and, if I don't succeed, I'll be out
searching for it.

Thanks again :-)

[Loony]

Hello once more :-)

I found some RCA cables and I came across an interesting RCA document:
http://en.wikipedia.org/wiki/RCA_connector. It appears that some
connections with RCA cables can cause damage.

For my car a cable had a male connector on one end and two males (cream
and red) at the other. I thought I could connect them to the red and
cream female connections that come from the radio. I got that set up and
then looked for a round female connector on the Garmin. It wasn't there,
or at least I could not find one. What a waste of time???
There is a small slot on the Garmin but it is for some kind of cards.

I then looked at my Nokia and found that its female connection is an
exact fit for the cable mentioned in the above paragraph, so I guess it
wasn't a complete waste of time. What would be the advantage of this
connection?

What now???

Have a great weekend Tiger! :-)