Electrical Diagnosis

[79_vetter]

Anybody got any ideas why gauges ( oil, volts, and fuel ) would quit working when lights are turned on? I've noticed that if I turn the instrument panel lights off by dimming them way down, gauges come back on.... I suspect bad ground,maybe.

 

[KenSny]

Sounds exactly like a short to ground. But finding out where is going to be a big PITA. You will probably need to go behind the cluster. First I'd pull the light switch and take a look at it and any wires in the back. You might get away with only lifting the top dash to see the harness.

 

[vigman]

Eeeeeekkkkkkkkk

So in that year you have 2 problems,
1)The standard wiring OH BY THE WAYS
2)There is a Flex PC board on the back of the center gauge cluster, over time, the elements on the pc board ( read copper film between 2 layers of thin plastic...CHEEP) start to seperate and the connections get poor.


Now the BAD news

You will have to pull the assy apart and inspect it.

Is there an after market stereo/ alarm installed?

Mike

 

[sac001]

I think the printed circuit board on the back of the gage cluster is a good place to start. When I bought my 80, the center gage lights didn't work, and after pulling the radio and cluster, I found the circuit board fried at the connector at the top.

I plan on replacing the radio anyway, so I just left it alone for now, but the plan is to replace it in the spring, and hopefully get my lights back.

Good luck!

Steve

 

[Bob Chadwick]

I had circuit board problems as well. Some of my gauges weren't working like they should. Got a new one at http://www.tld-corvette.com/ for about $125. Money well spent. The old one was coming apart, was not getting the proper ground, etc. While the instrument shop said they could fix it by soldering wires, it was just a matter of time so I took the plunge.

Bob

 

[vigman]

Don't try to fix it!

( meaning the old board)

It's like a british car.. it will just leak somwhere else.

UNLESS THE BOARD IS PERFECT then clean all the contact points , a pencil eraser works great for that.

look at the edges for seperation..if it is TRASH IT!

There is NOTHING more of a Pi$$er than an intermittant.

Mike