heinrich

Messing with switches and rheostats will fix the illumination issue but it won't help with the stereo and low voltage issues. The answer to the problem may lie behind the pod but the instruments themselves are not causing this issue.

syoo8

Hi everyone,

Thank you to all of you for your valuable input. I hope this thread benefits other newbies-- it certainly has helped me. Thank you especially to my mentor Heinrich for starting this thread.

The good: I took apart the instrument pod last night, removed the circuit board from the plastic and cleaned every f***ing piece of copper that I could find. The instrument pod and everything inside it is clean. I also cleaned the 68 ohm resistor that is part of the voltmeter circuitry. Before I cleaned it, it read between 90-105 ohms. Afterwards, around 72 ohms.

The bad: No difference whatsoever in the reading of the voltmeter.

What do I clean next?

Alan

Front jump post? test the voltage at the top of CE panel?

The other connections to the pod are the plugs at the bottom of the CE panel - particularly plug pin J14 & Fuse 10 connections - (4th pin up on the left bank of plug J) probe into the back of the plug & test the fuse in circuit via the sunken probe pad on the back (on most fuses).

Alan

syoo8

Hi Alan,

I cleaned the power and ground at the top of the CE panel. Also went ahead and cleaned all the battery contacts, etc. Cleaned the ground wire behind the front jump post, and also the one next to the radiator on the left (which is a pain in the ***.)

12.28 volts at the top of the CE panel with the engine off, 13.45 volts with engine on.

Is this normal?

Alan

What is the voltage direct across the battery terminals - its really the difference that tells you what is going on - but 12.28v with the ignition off is too low.

13.45v running is probably OK - but again its the comparison that is most interesting - this time compare to the jump post since that is closest to the alternator connection.

Alan

syoo8

Ugh, Alan-- sorry to keep bombarding you with questions. I owe you a great meal, next time we are in the same city together.

Voltage across battery terminals is 12.71 volts. Normal.

So am I correct in saying that by the time the power gets to the top of the CE panel it is already too low? Does this mean that there is some kind of voltage drop between the battery and the CE panel? Where is that coming from?

Alan

Yes - exactly - you are seeing a voltage drop and there should be none with the ignition off and basically no load on the battery (or at least a very very small load)..

This was with the ignition off right?

The ground is through the chassis & back to the battery via the battery ground strap. The positive connection comes from the battery +ve straight under the car to the starter, on to the alternator, on to the jump post and on to the top of the CE panel. The pod/instruments are fed from the CE panel. I'd suggest you measure voltage at each of these points to see where the drop occurs... the jump post would be next tracing backwards. Be careful you have a good ground to the chassis in each case...

Alan

syoo8

Also....

At the jump post, engine on: 13.99 volts.
At the battery terminal, engine on: 13.90 volts.
At the CE, engine on: 13.92 volts.

At the jump post, engine off: 12.59 volts.
At the battery terminal, engine off: 12.68 volts.
At the CE, engine off: 12.68 volts.

Alan

The first three make some sense - the last three have me confused - can you retry those for confirmation? I'd expect battery to be highest jump post next & CE the lowest...

Alan

syoo8

Well, the engine was off. Ignition was ON.

Alan, I went through and checked with the ignition off. We are looking pretty good.

Is it possible, given the voltmeter readings below, that my cockpit voltmeter just reads low? (Remember that I completely cleaned the circuit board the other day.)

Ignition off:
Battery terminal: 12.78 volts.
Jump post: 12.78 volts.
CE Panel: 12.76 volts.
Instrument voltmeter: N/A

Ignition on, engine off:
Battery terminal: 12.68 volts.
Jump post: 12.59 volts.
CE Panel: 12.68 volts.
Instrument voltmeter: 10 volts (approx)

Engine on:
Battery terminal: 13.90 volts.
Jump post: 13.99 volts.
CE Panel: 13.92 volts.
Instrument voltmeter: 12 volts (approx)

syoo8

Did them again: Ignition ON, engine off:
Battery: 12.50 volts
CE: 12.37 volts
Jump Post: 12.20 volts
Cockpit "10" volts

heinrich

Scott, I kinda need to ask at this point, are you still seeing the illuminated brights light and does the stereo still wink out?

heinrich

It's sort of looking like maybe the problem lies in the engine compartment?

Alan

Can you redo the middle set of number s too?

Based on the way this should be wired these seem a little odd... the jump post should always be higher than the CE panel top. What ground are you using for the CE panel test & the jump post test? do you have a long enough wire to use the battery -ve post for all the measurements?

I would propose we also try a few experiments... what seems to be happening is:

a) You may have a larger than normal electrical load with the ignition on
b) Your dashboard voltmeter reads significantly low all the time...

We should solve a) first - it may help with b)

With ignition on & monitoring the top of the CE panel connection - see what happens to the voltage as you do these things:

Turn off the AC & Blower
Remove rear defroster fuse
Remove Seat Heater fuse (if equipped)
Pull fuses for the 2 cooling fans
pull fuse for flap motor if equipped
pull fuse for headlight motor

Try these and see if any one of them makes any major difference?

Alan

syoo8

Hello Alan and Heinrich-

I redid all the measurements this morning, using a 10 foot-long wire connected to the wingnut strap as my "ground." Here's what I came up with.

Heinrich-- yes, the blue high-beam indicator light in the instrument cluster still comes on when I use the headlights in low-beam. And yes, the radio still cuts out.