dcdrechsel

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dcdrechsel

Few more questions -are the fuses the correct rating ? Has any work been done on the electrical system ? The reason for the questions is that b3 and b4 should not affect the instrument cluster .It would seem that there could be another issue lurking .What are the instrument cluster funky symptoms ?

RBC

Yes, the fuses are absolutely the correct rating. The only electrical work that was done was a battery replacement about 9 months ago, and the ignition switch I replaced last week, otherwise the car is bone stock. Of course, I've since come to find out that the ignition switch isn't even in the circuit.

It looks like B1, B10 and E1 are the fuses for the cluster. Out of the blue while driving the car a couple of weeks ago, every light on the cluster just started blinking on and off, in a rhythmic pattern. The gauges went dead, and the fuel gauge was jumping with the blinking lights.

What's odd, is that even though B1 is not evidently routed through the ignition circuit, when I turn the key to the ignition position, the voltage at B1 plunges to 7.76 volts. Even more curious, is if I pull the B10 fuse, voltage at B1 goes up by 1 volt. Somehow there must be an interrelation between B1 and B10.

Strangest thing I've come across, including cars, boats and motorcycles!

dcdrechsel

You might want to check f6 as well .It seems to be a poor connection issue .

dcdrechsel

Also the positive battery cable

RBC

Thanks...I'll start with the fuse box and work back.

dcdrechsel

good luck -look for chewed wires the symptoms are similar to mice gnawed wires

RBC

OK, you guys aren't going to be happy with me... I've been measuring voltage across the fuse. So, measuring the 12V+ side of the fuse, and grounding to chassis, I'm getting 12.4V across fuses B1 - B4. I measured all the way from the battery, to the fuse box, only to realize my error. What a dope I am.

Anyway, I think I've ruled out the battery, charging system, current distributor, fuse box, and fuses. My next step is to measure voltage at the cluster power connector. If I have 12V+ there, I believe it would be safe to assume the issue is with the cluster itself.

Is there a pin-out number diagram of the black connector on the back of the cluster?

Sorry for the wild goose chase, I know you guys have been getting a headache over this one.

RBC

Never mind, with a magnifying glass, I can make out the pins! I'll report back....

RBC

OK, I checked voltage at the 12V pins on the connector, from both grounds, and I'm getting 12V+ from all of them.

I think/hope it's safe to assume it's the cluster itself. I'm nowhere near capable of repairing the cluster, unless something is glaringly obvious, so I'll have to send it out.

My last question is, how the heck do you get the wiring harness off the back of the hazard switch?

cds72911

As I recall: Pull the switch out from the front, the harness drops down vertically. It is in a slot in the plastic of the dash.

RBC

Thanks! Got it out, and have the cluster on my desk. Guess I need to find someone to bench test it, as I have no clue how to troubleshoot it!

dcdrechsel

No problem -on the instrument cluster there is a very knowledgeable Porsche person in south florida -which you can get to by googling Pedros garage .I would call Pedro and see what he recommends .Porsche instrument clusters can get to be an expensive slippery slope -Pedro may be able to point you in the right direction

RBC

Thanks again for all of the help! My local indy recommends a place called Southern Speedometer in Clearwater, FL. He evidently sends all of his instrument clusters there, but I'll also check out Pedro's Garage.