Printed circuit burned on trace going to lower right pin two

[jtapps]

My printed circuit burned the trace going to lower right connector pin 2 "Masse" or ground.

The 5th pin from left reads masse as well but has a differnt color wire as pictured.
This resulted in my cluster lights going out. I am supicious of the dimmer potentiometer and the cluster connector wiring. I changed the blue black wires on the pot to go to the lower connector as they were on the upper when I got the car with non-working circuit card.

Should pins 2 and 5 from left on the right cluster connector both be brown wires as the wire is in pin 2 pictured.

Sorry, first post so will just throw some pics up.

[jtapps]

Car is 1980 Euro S by the way and for clarity, I burned mine in the exact same place as the burn where this jumper is, from another post by Rupesy..

'79 Speedo not working

[Landseer]

Have you checked in your console, near the base, in vicinity of ashtray? I've found several cars with heat / fray / chew damage in that area and its the same circuit -- could be contributory.

Any other thoughts on cause?

[jtapps]

Thanks for the quick reply. I will check there as well. I saw some loose ground wires brown / white under steering column as well as some creative wiring and use of colors by PO. Cleaned battery, ground strap, and contacts, went looking for the ground spot in the engine, but i think I located the positive block on passenger side fender above compressor. Cleaned that as well.

I am suspect about the positions 2 and 5 "MASSE" on the lower right cluster connector with two colored wires as in my cluster connector pic. The wire on 5 is not the same color.

When I got the car, the cluster did not work but the tach and right guages.

How can I eliminate the potentiometer dash dimmer, just join those wires blk / and black - blue. Mine has that 4 pin molex connector coming off the potentiometer and washer button.

[Landseer]

Yes you can bridge across the potentiometer for the lights.
There might be another one on the opposite side for intermittent wipers?

[jtapps]

yes there is another one for intermittent, but it is yellow / red and yellow pair, looks ok from what i have seen

[JhwShark]

I'm not sure if you have a wiring/current flow diagram, it can help you trace. These may help...Manuals...scroll down to find what you need.

[jtapps]

Thanks JhwShark. The cannell site is familiar, I downloaded these a long time ago for the 89 S4, but haven't been back since. I'll report back after I get back out to the garage this weekend.

I sure hope I don't have to trace the cluster connectors out, but printed circuits are not cheap and it seemed to jump from $120.00 to $287.00 for whatever reason...

Have a 930 S wheel on the way, but can't put it on and drive the car due to the wiring issues. At worst if it fries again, it is no pod lights, and temp guage flaky. All others were working after the scorch.

[jtapps]

Good idea JhwShark. I was thinking of the shop manuals, and combing through them is cumbersome in pdf format to find what you need. But the current flow diagram is great. I just wish I were better at these diagrams, I like pics and layman descriptions. But I am cheap, so I will be motivated not to fry another circuit trace!

[jtapps]

Well as for lead numbers, the MASSE contacts are pins 7 and 11 on the lower right connector to cluster.

My grounds match up, so i cleaned their attach points and will check fuses for illumination. I feel that there must be a hot wire in the ground circuit with a crosswire somewhere on the switches.




note the odd 4th switch taped in blue and spliced into the leads for the dimmer pot and intensive wiper push button


i think it may be one of these two, the dimmer pot or the washer push button, i have

[jtapps]

meant to have my printed circuit lower right pic included as well next to the connector.... The MASSE loop is from PIN 11 and PIN 7 which matches my connector and i did a connectivity check with tone and connectivity tool

[Landseer]

What's that crazy cobbled-up trailer light harness doing there?

There is an extra Euro light socket taped up inside all these dashes.

[jtapps]

Would that be a freebie from Porsche? lol

Why is it half wired up?

[Landseer]

Its for the rear foglight. All the cars got certain remnants of wiring across markets.

On the Euro cars, the bottom left switch is the rear foglight. That's the fixture you found. Usually its tapped with old beige masking tape.

The odo reset switch is replaced with something under the dash instead.

[jtapps]

Thanks, I do know my rear foglight worked prior to going in. That is why I was confused about the push buttons, because I believe one is for trip reset and one is for intensive wash. I know that some cars have two pushbutton switches intensive wash and trip reset and two potentiometers dimmer and wiper delay. While in holding pattern for fuses, I was in the panel and found at least 7 fuses that are coated in white paint or corrosion. Not sure if they are dummy fuses, but I have only 2 "not used" slots in the 80 Euro S.

I took a dremel with a nice hard rubber disc which was thin enough to do the middle and both ends of the bullet fuses until they had a nice shine and are now conductive. 7 and 13 were not used if I recall, but I cleaned about 5 others. I think 11 and 12 are for instrument lighting among a few other things. Both looked shoddy, but they have continuity now at least. I am soon going to reapply power to the cluster with the new printed circuit. I just want to be sure there is no hot line in my ground circuit.

Is there any risk in putting the wrong white switches in the wrong white plugs for the rear fog light and the fog light switches? I am referring to the white switches you see when you pull off the buttons in position 2 and 3 on left of pod.

[JhwShark]

Originally Posted by Landseer

Its for the rear foglight. All the cars got certain remnants of wiring across markets.

On the Euro cars, the bottom left switch is the rear foglight. That's the fixture you found. Usually its tapped with old beige masking tape.

The odo reset switch is replaced with something under the dash instead.

Thanks...good info diferentiating between Euro and US...good to know!

[gbgastowers]

Originally Posted by jtapps

I am soon going to reapply power to the cluster with the new printed circuit. I just want to be sure there is no hot line in my ground circuit.

Is there any risk in putting the wrong white switches in the wrong white plugs for the rear fog light and the fog light switches? I am referring to the white switches you see when you pull off the buttons in position 2 and 3 on left of pod.

Where did you get a new printed circuit board? It looks like I need one also. My rebuild didn't work even though it looked like it should have. I have several gauges not working and no instrument illumination. All the warning lights work though. There is a place in Greensboro,NC that is a well known VDO rebuilder. Gunar

[JhwShark]

Check with 928 International for your the board...

[jtapps]

@ gbgastowers

Yes, I got the printed circuit here at pelican, nut the price is way up from weeks ago. It more than doubled to $287 now. It is for 79-81 and you were 82.

928 International - Printed Circuit 79-81 - Printed Circuit 79-81 - shop.928intl.com

I will keep my eyes peeled for you.
I may have some parts for you once I get mine working.

Updates:

I just replaced all fuses tonight and properly replaced all oddball Amperage fuses. There were 25A fuses in 8 slots which is probably why it allowed the damn thing to fry my cluster.

I used the rubber disk dremel attachment on a lower speed and cleaned every fuse socket. I cannot stress enough that I was astounded that so many fuses where a corroded white powder coated look with no continuity, yet were somehow "working" systems. I first cleaned them, then just replaced the aluminum fuses with the newer brass / ceramic bullets.

I closed up the fuse panel. Getting closer to applying the "All Spark" to the cluster!

Here are my shiny new fuses.

Here is the german cluster that I am installing in place of my mph euro cluster
it came in rough shape,


I used mothers and meguiars headlight restoration, only the foam rotary on a drill, no sandpaper and it looks new! I love the red needles, just like on my 04 2.7T Audi!

[jtapps]

Update:

-Tried new cluster, replaced all fuses.
-No tach, (will try with known good)
-Fuel registers full, voltage registers.
-Warning lights seem to work, handbrake, Stop Brake, etc..
-One 3W on but no others.


This cluster was from a german 80 manual / mine previous is 80 S automatic.

-I disconnected fuse 23 which controls interior lights just to be sure there wasn't something interfering.
-My headlights work, external blinkers work, fogs, driving, rear fog all work. Car starts and runs. No dash lights with lights on or off, well one light is on bottom right 3w.
-I shorted the wires black to black / blue for the potentiometer (dimmer) left side to bypass it, no change.
- Mileage Reset Works - Tested the black pushbutton under my dash for mileage reset and it works.
-Turn signals click and work outside, but not in cluster light


If anyone has a picture of the wire pinouts for an 80 Euro S as they are on the cluster cable I would appreciate it for comparison. My 3 printed circuits all read tacho for pin 1 left connector, the flow diagrams specify this wire as green or something. My wire is not green.

I think the PO has moved things around.

1. Does anyone know which leads on the L R and Center connectors would give the dash illumination and what their wire colors are?

2. Any other ideas as to why it is not working?
If bypassing my potentiometer did not work, then maybe these wires have no current eh?