911sc Head ligh and ignition problem, connected issues???

[runehar]

Last night i was trying to work out some light issues on my car (1980 sc with turbo engine and electromotive ignition, got it one week ago). I didn't do much except connecting the wiring to the back up light swich on the transmission.

the engine started fine and the headlights and instrument lights worked fine before i started my "work" , but all of a sudden the headlight doesn't work, the turn signals doesn't work and the engine doesn't start. (it turns over and i can hear the fuel pump)...

My first taught was that the headlight switch was busted (havent tried to short cut it yet), but i don't see any connection between the headlight and the engine won't start problem.. Is there something i don't get, or is this just a coincidence??

Hopefully i have some time to try figuring it out tomorrow, but if anyone has good suggestions i'd appreciate it

thanks
Rune H.

so to my question: Is there any "conneciton" between lights and ignition

[Weissach Mike]

Rune,

I have only had a 911 a short while,but I am pretty familiar with 912's. I think that the backup light switch has one always hot wire and one that is only hot when reverse is selected and the interal pin completes the circuit. So you went to this switch to just grab power ? The output on this circuit is probably low also. I assume that you have checked your fuses. I think it might be helpful to run the wires to a known good circuit that has high amperage. Possibly just patch in temporary wires to good source and see if it corrects the problem.

Good luck,

Mike

[86 911 Targa]

Originally Posted by runehar

Last night i was trying to work out some light issues on my car (1980 sc with turbo engine and electromotive ignition, got it one week ago). I didn't do much except connecting the wiring to the back up light swich on the transmission.

the engine started fine and the headlights and instrument lights worked fine before i started my "work" , but all of a sudden the headlight doesn't work, the turn signals doesn't work and the engine doesn't start. (it turns over and i can hear the fuel pump)...

My first taught was that the headlight switch was busted (havent tried to short cut it yet), but i don't see any connection between the headlight and the engine won't start problem.. Is there something i don't get, or is this just a coincidence??

Hopefully i have some time to try figuring it out tomorrow, but if anyone has good suggestions i'd appreciate it

thanks
Rune H.

so to my question: Is there any "conneciton" between lights and ignition

Rune,

Undo what you did, buy a Bentley bible, and a multimeter on eBay.......

Good luck,

Gerry