C3 - backup lights

[Jim K.]

My backup lights failed a tech test this weekend and I started trouble shooting last night.
I turned on the key with my 71 4 speed in reverse. Lights did not come on. But, about 20 seconds latter they came on while I was not even near the car. Went out about a minute later.
This sequence repeated 3 times and the last time the lights did not go out. And now the lights work all the time.
This entire sequence happen by only turning the key on and off and not touching the car in any way. Any ideas what this could be or where to look? Jim

[Chuck R.]

Re: C3 - backup lights

Sounds like maybe your backup light switch on the tranny is heading south on you.

Check your wire connections there first. If they look good, pull the feed wire off. If the lights go out, then I would say that the switch is the culprit. If not, you will have to start tracing and looking for touching bare wires.

Be careful though, those backup switche connections can be pretty fragile sometimes.

Chuck 32205

[Jack H.]

Also....

B/U light switch wiring from the tranny to the mating connector on the firewall was routed through a firewall clip to KEEP it from moving and touching the LH exhaust pipe. Frequently, you'll see prior bubba mechanics simply let the lower portion of the cable to the B/U lamp switch 'hang' in the breeze and, with visual inspection, you can discover exhaust pipe burn damage....