71 Corvette electrical short

[Mike Sealy]

I have a strange electrical problem in my 71 Vette. The courtesy lamp fuse continues to blow. When I replace, the courtesy lamps work properly but the light for the transmission indicator lamp is ON with the headlamps off and ignition off.

When the lights are turned ON, the transmission indicator lamp goes off.

This problem occured after I replaced my console plate. Everything is reconnected, but noticed my Heating and AC control light is very dim in the console. Where could I have created a ground problem with what little I did?

[Terry M.]

Re: 71 Corvette electrical short

Best idea I can think of is to go back over what you did and see where you might have pinched a wire. Sounds like you shorted something out in the console. there is not a lot of room under there and a lot of hoses and wires are placed into a small area.

Terry McManmon

[Terry M.]

Re: 71 Corvette electrical short

Best idea I can think of is to go back over what you did and see where you might have pinched a wire. Sounds like you shorted something out in the console. there is not a lot of room under there and a lot of hoses and wires are placed into a small area.

Terry McManmon

[Jack H.]

Re: 71 Corvette electrical short

Educated guess is you're fighting separate 'ghosts'....

Courtesy lamps are independent of other circuits EXCEPT for sharing a common B+ (see wiring diagram). Typical generator of blowing fuses w.r.t. interior lamps is flakey pillar post switch/wiring.

Path is from fuse, to BOTH/EITHER door switches, to lamp loads, to ground. Door switches are mounted in bird cage at front of door jam. Deep dish socket will remove switch and CAREFUL wiggling/pulling will extract switch on excess wiring out of bird cage/door jam.

Inspect switch for frayed wire and/or broken 'hanging' leads. Inside of bird cage is metal/ground often worn and damaged by prior 'gorilla' mechanics and/or water leak damage (sloppy/bad windshield gasket/seal).

If lead wires to door post switches have degree of freedom to short to ground (or hanging debris from water damage, prior owner 'customization' can effect same), the net result is B+ shorts to ground WITHOUT resistive load of lamp filaments and bye bye fuse....

[Jack H.]

Re: 71 Corvette electrical short

Educated guess is you're fighting separate 'ghosts'....

Courtesy lamps are independent of other circuits EXCEPT for sharing a common B+ (see wiring diagram). Typical generator of blowing fuses w.r.t. interior lamps is flakey pillar post switch/wiring.

Path is from fuse, to BOTH/EITHER door switches, to lamp loads, to ground. Door switches are mounted in bird cage at front of door jam. Deep dish socket will remove switch and CAREFUL wiggling/pulling will extract switch on excess wiring out of bird cage/door jam.

Inspect switch for frayed wire and/or broken 'hanging' leads. Inside of bird cage is metal/ground often worn and damaged by prior 'gorilla' mechanics and/or water leak damage (sloppy/bad windshield gasket/seal).

If lead wires to door post switches have degree of freedom to short to ground (or hanging debris from water damage, prior owner 'customization' can effect same), the net result is B+ shorts to ground WITHOUT resistive load of lamp filaments and bye bye fuse....

[Tom B.]

Re: 71 Corvette electrical short

Mike,

My first thought after reading your post was whether or not your console was grounded correctly. But I think the problem is more like what Terry and Jack have said separately:

1) More than one problem and 2) a pinched wire (or a "hot" one) that would be grounding out.

Still, with my original thought, you might want to check the 71 AIM and see where your console ground connects. I replaced the wiring in my 68 (and knowing that the 71 may be wired a little differently) there is a console ground that connects to a tab screwed into the underside near the ash tray. Also you might want to make sure your upper console is making contact with a ground. Just information, hope it can help. Tom #24014

[Tom B.]

Re: 71 Corvette electrical short

Mike,

My first thought after reading your post was whether or not your console was grounded correctly. But I think the problem is more like what Terry and Jack have said separately:

1) More than one problem and 2) a pinched wire (or a "hot" one) that would be grounding out.

Still, with my original thought, you might want to check the 71 AIM and see where your console ground connects. I replaced the wiring in my 68 (and knowing that the 71 may be wired a little differently) there is a console ground that connects to a tab screwed into the underside near the ash tray. Also you might want to make sure your upper console is making contact with a ground. Just information, hope it can help. Tom #24014

[Jack H.]

Another thought....

Door pillar post circuit runs unswitched (don't have to have key in ignition for lamps to come on when door opens). Also, the cigarette lighter works the same way (unswitched).

You had center console apart. B+ lead to cigarette lighter is slip-on to the base of the lighter barrel via nut attached wafer contact. There ARE metal items under the console (reinforcement ribs, Etc.) that are electrically grounded.

Is is possible you forgot to reconnect the ligher B+ lead properly when you re-installed the console plate and/or managed to deform the lead/contact?????

[Jack H.]

Another thought....

Door pillar post circuit runs unswitched (don't have to have key in ignition for lamps to come on when door opens). Also, the cigarette lighter works the same way (unswitched).

You had center console apart. B+ lead to cigarette lighter is slip-on to the base of the lighter barrel via nut attached wafer contact. There ARE metal items under the console (reinforcement ribs, Etc.) that are electrically grounded.

Is is possible you forgot to reconnect the ligher B+ lead properly when you re-installed the console plate and/or managed to deform the lead/contact?????