Dean_Fuller

I have probably bored everyone with the original thread on Garrett's car so most may not be reading that now so I will try here . I have Garrett's car almost complete now. The car starts, runs and shifts as well as it did 2 1/2 years ago when I started taking it apart. All exterior lights work as they should EXCEPT NO Brake lights.

After installing the instrument cluster and a test drive here is what is happening.

Temp gauge......pegs max hot right away.
Gas gauge shows 3/4 tank with 8 gallons in.
Speedo..............not working.
Tach..................works
alt gauge............not working
oil pressure.........not working
No gauge lights.
high beam indicator ON when regular head lights on, and OFF when high beams on.
Driving lights work but when ON the fog lights stay on too.
Also NO Brake lights.
Whippers not working.

I think all else works.

What I have tried.
Cleaned grounds under steering column twice.
Cleaned grounds at pass rear corner.
Cleaned main battery ground.
Checked all fuses.
Reseated all main connectors in fuse panel.
Reseated all relays.


The film on the back of the instrument cluster is dry and brittle. The three main plug ins had several contacts "roll up" and I re glued them down and scrapped off any glue residue on top with a razor blade. I cleaned contacts with a eraser and sprayed cleaner down into female plugs.

After reading Dwayne's write up on cluster repair he stated he had erratic needle movement after touching the back of the panel around the rivets. I tried that with no reaction at all in any needles.

I am not good at electrics...where do I start?

Is there a way to see it power is getting to the cluster lights?

With this much not working I would think its a ground or a short ( no blown fuses ) .

Any help, ideas would be great !!!!

Jadz928

Hi Dean,
You said you checked the fuses. Did you also clean all the fuse contacts? They may look okay but it's misleading as the corrosion collects right at the edge where the fuse seats.

A new printed circuit is almost $300 new, OUCH!
http://www.mailordercentral.com/928i...928 641 939 00

We gotta find a way to get you a better flex PCB.

Dean_Fuller

I checked voltage at both ends of fuse 10 and 12. I have just under 12 volts at both ends so I would think the fuse is doing its job.

Yep...$$$$ and thats USED so it may not be any better than what I have.

Dean_Fuller

I cleaned the fuse panel when it was out of the car and stored inside. It was about a year a go but again...stored inside.

Dean_Fuller

Well I think I may of found the problem. Its much worse than I thought. The card has become
de-laminated. I think I will need another one. Thoughts on if this one can be saved and how?

Thanks.

depami

Tedious and time consuming but fine wire and super glue should do the trick.

Use fine, highly flexible multi-strand wire (I pealed individual wires off of computer ribbon cable and used that) and glue it to the existing flex panel following the original traces. Only glue on the "flats", don't glue on the bends or flex points.

Carefully solder the wire to the flex circuit pads. Pre-tin both parts to allow for a quick, minimal heat connection. Just enough heat to get a good joint as the flex circuit melts easily. Of course you need to remove the material over the conductive film before soldering.

Slightly notch the edge plastic at the connectors at each contact to keep wire from sliding.

Cut wire long enough to overlap edge by a half inch or so.

Do a partial strip to slightly past edge.

Twist and tin the exposed wire to keep it from being flattened by connector.

Fold remainder over edge in previously cut notches and super glue to other side.

Trim excess on back side if necessary.

If the edge connection is good on a particular circuit, you may be able to "spot patch" by bridging over bad areas with this same method.


Sorry, no pictures but it worked for me on my ’82. I didn’t do them all, just the bad ones.

I also soldered all the “feed through” rivets.

Good luck.

Podguy

Dean,

I have seen worse. First you need a good VOM, the wiring diagram printed out and expanded, and a lot of patience.

You can check the resistance of the paths on the circuit board. You may find most are better than you think. The ones with high resistance can be by passed as suggest above.

The temp gauge might be wired incorrectly at the engine.
The gas gauge might be a result of a stuck sending unit. They can be disassembled and cleaned. There are two circuits - one for the empty light and the other for the gauge.
The speedometer is controlled from a pulse from the differential. The wires from the sender connect in the spare tire well. You can test the sender by using a magnet.
Power for the dash lights starts at the rheostat on the pod. Make sure you have power in and then trace forward.
I believe the brake lights on your car are controlled by two sensors on your master cylinder. That is the place to start.
Check the electrical portion of the ignition switch. These wear and can cause all kinds strange problems especially with the lights.

Orantes

I think you're wrong about everyone being bored with your original thread. It's definitely one of my favourites!

Dean_Fuller

Thanks ..Lots of good direction again. Will report back asap.

chrly924s

Dean, I soldiered new wires to the card where the plugs clip on on the silver '81. I have pictures. That fixed that and everything works better. Your's looks a little worse. The taps were delaminating on mine; not the whole card. I you got no broken circuits on the card, you may be able to contact cement the plastic back to the circuits. It the tabs are delaminating, then they won't go into the plugs, causing all sorts of things to work wrong/not work.

WICruiser

You may want to check that the female edge connectors are not buried in the plastic housings preventing them from making contact with the foil. I used a dental pick to lift each side of each terminal and bend them inward so that they are a tight fit on the foil. It substantially changed my speedo and tach performance but also seems to have influneced all of the guages.

Fogey1

Are these threads any help?

Gauge Cluster to LED & solid wire conversion
https://rennlist.com/forums/928-foru...ml#post8190293

Who will rebuild a 928 Gauge Cluster?
https://rennlist.com/forums/928-foru...e-cluster.html

Dean_Fuller

Thanks Will...those are great threads.

Mark Anderson

Dean,

Your efforts on this project are inspirational in many ways. Your present electrical issues seem as though many of them could be resolved by a good PCB. There is an anonymous group of 928 members who would like to provide you with a good condition PCB for your car. 928 Int'l is here to facilitate that offer. If you PM me your address we will ship it out today.

Dean_Fuller

I am BLOWN away by the help my son has gotten on this project. I hope to repay to all that have help soon in some way. Thank you all from the bottom of my heart.