Tach and Temp Lights out

[Steve101]

I just bought this 1987 325e and the lights for the tach and temp were out. also the odometer was not working.
When I replaced the gears for the odometer, I checked all the lamps in the instrument panel and the batteries on the S.I. board (3 volts each).
I also went as far as, lighting up the lamps with a power suply.
Also the tach seems to work and I think the temp was working too, just not lighting up.
The S.I. is on, but I was just going to reset that later.....

Any ideas on why the tach and temp lights won't come on ?

Thanks
Steve

[Steve101]

Found problem.... It was a bad track on the back of the instrument panel.

[cbradfordg]

so how'd you fix it?

[Driver Ed]

I've read that one typical problem is solder problems on the back of the instrument cluster. The usual fix for this is to remove the instrument cluster and just heat up each of the solder joints enough to reflow the solder. After many years of vibration, the solder joints can fail.

[Steve101]

This is very frustrating.........
I have tried twice and a lot of time.... every time I submit to the forum, it kicks it out and says I'm not loged in.....

If I was not logged in, I could not get to the reply post.....

Steve

[jase007]

Steve:

You can see the forum ... and not be logged in. If your browser [or you] don't let the site set cookies then when you return ... youa ren't logged in.

Jase

[Steve101]

I hope this works. I'm using note pade to copy and paste.

My Problem was not a bad solder joint.

I found that there are 2 wires Brown w/White and Gray w/Red
that go from the Head Light switch to the I.P.(Instrument Panel).

It goes in on the left side (White Plug) of I.P. and out in the
center(Yellow Plug). Then it goes to the Clock.

Problem:
There is a track on the circuit board in the I.P.
that goes around a screw hole and was made very thin.
The resistance on mine, was 10.4 ohms but should be zero.

Location:
There is a hole above the speedometer, just at the edge
of the circuit board(I have pictures if needed). The thin track
goes between the hole and the edge of the board.

Fix:
1. remove the I.P.
2. open up the I.P. and locate the track
3. I used a knife to scrape off the coating(paint?)that covered
that thin part of the track until I got to the copper track.
4. with a low power soldering iron(15 watts) I added solder on top
of the thin copper track.
5. recheck the resistance for zero ohms.
6. Used my wifes clear finger nail polish to cover repair.
note: If you have not soldered very much you may want to get help.
Just don't let the track get too hot. Just put a little solder
on the tip of the iron and wipe it across the track.
It may take a few wipes.

You know, I bet you could just check if this is your problem
with out taking out the I.P. by checking resitance from head light
switch to your Clock.


Steve

[jase007]

Nice fix Steve.

Email me the pic and I'll put it in a post on this thread for reference.

Jase

[Driver Ed]

I'll have to look for that when I pull my instrument cluster this weekend.

[Steve101]

Correction: the area to look at is above the tach.

Wanted to see if I could add the picture.
jase007, I'll also send you the email.