Sacredgrooves

I obviously have a problem with a wire somewhere since my fuse popped twice. any ideas where to start? my first consideration is the radio since sometimes it works,sometimes it doesnt. could have a loose connection there popping the circuit fuse for the instrument lights or is that on a different circuit? (clock on aftermarket radio always works regardless but I THINK that is hooked to a constant power source?)

70sgeek

bad ground is usually the first culprit.. If you have a factory service manual, trace your chassis ground(s) and look for problem issues in the wiring (frayed, broken wire) . If the back of your gauge cluster has a ground terminal, check to see that the harness wire is still connected to it. If it is, disconnect it and run a test lead from the terminal to the ( - ) batt terminal. If you don't blow any more fuses, you can at least isolate the problem to your dash harness.

Hope that helps at least a little bit...

comp

don't leave the batt. connected when it just sitting

SLVRSHRK

I had a similar issue with my car when I purchased it. In fact, I had found several receipts where the previous owner had taken the car to a service station because the cigarette lighter fuse had blown (same as interior lights). The service station just changed the fuse and it would work for a while.

Took me a while to track down but the solution was amusing. First question; is your car a manual?

I ask because mine is and that's important because the cotter pin on that attaches the clutch linkage to the pedal assembly was grabbing at a wiring harness and had chewed through the insulation on an orange wire. These wires are the power sides of the interior light and other circuits.

Anyways, sometimes wen the clutch was depressed (by my foot, not because I don't drive the car enough), it would hit the wire and ground it out, which would blow the fuse.

Here is a link to the courtesy light circuit on a 78 (I realize yours is older by the picture in yor sig, but it's a good start).

http://corvetteforum.net/c3/tunedpor.../index19.shtml

I would start under the dash on the driver side.

Good luck, it took me several months to track my issue down.

72LS1Vette

You are right about the radio clock. Radios have a constant +12 for the clock and memory and a switched +12 for the other radio functions. The solution to the problem might be easy or it might be very difficult - no way to tell over the Internet. You have to get a schematic and look at every component that is on the circuit that is blowing the fuse. Does the fuse blow immediately when you replace it? That would indicate a dead short. If the fuse blows when you turn on the lights, look at the light switch. If you know the series of event that cause the fuse to blow, start disconnecting every component in the circuit until you isolate what is blowing the fuse.

To give you an idea of how tricky these things can be, my son had a car that was blowing the instrument cluster fuse. I would replace the fuse, everything was fine, and the next day when he started the car after school the fuse was blown again. Turned out that a wire in the console had gotten caught in the e-brake mechanism and abraded. When he got to school each day he would shut off the car, pull up the ebrake handle and leave. after school when he started the car the wire was grounded out and blew the fuse. Of course every time I replaced the fuse the e-brake was off so the fuse didn't blow. Took a couple boxes of fuses and a good look at the schematics to figure that one out.

Rick B.

Sacredgrooves

thanks for the replies everyone, you gave me some good places to start looking.
mine is a manual so I am looking there first.
I will put a new fuse in and test it at night to see if and when I can get it to pop. has to be intermittent because first time I changed it it lasted several months. the last time a couple days.

LABulldog

Mine did something similar. Check your cigarette lighter. Mine had shorted out (all rusted up in side, guess bubba spilled a drink in it or something). Changed out the lighter housing and everything worked again. Good Luck.



Jay