Yellow wire stays hot after start...wtf? help!

[Geneman]

hence engaging the solenoid and starter while motor running.... ugh i have burned out two hi torque racing starters until figured this out. $$$ but the strange thing is that if yu simply monitor the 12 volt signal from the yellow wire ( with the coil wire off, so motor does not start) , when you turn the key, it pulses the solenoid, then dies when the key flips back to run mode. all good.

however, if you do the same experiment and let the motor start and run, the 12 volt yellow wire signal continues, activting solenoid and starter and leading to nasty burnouts..

so is it the starter switch itself? or is there a separate relay for the yellow wire that is bad?

this is a 77 911 tub, converted to a 73 RSR full race car... but the PO maintaned all the original wiring. just in case..

thanks for your opinions frank

[boyt911sc]

Frank,

Check the yellow wire from ignition switch to terminal #1 (14-pin connector). Power @ terminal #1 should only be present with the ignition switch @ START position. No power @ #1 with ignition switch @ RUN position.

What type of starter are you using now? Do you have the 30/50 (2-wire) or 16/30/50 (3-wire) starter? The ‘76-‘77 use 2-wire type starter and ‘78-later use 3-wire type starter. Are you aware of these differences? There is something odd with your wiring to cause the starters to burn out. The solenoid should not be energized when you release the ignition switch to RUN position.

Tony

[timmy2]

If all wiring is original, there is no current path for the yellow wire to remain energized when key is released, Other than a sticking ignition switch, but you stated you tested and proved the switch releases to the run position.

Did a PO install a relay to help a previous weak starter?
If not, then maybe the switch mechanism in the high torque starter is hanging up.

[timmy2]

Good read here:
high-torque starter bit the dust (long)

[rwest]

I had the same problem and I want to say it turned out to be a factory relay that was defective- maybe the red fuel pump one? I did a thread on it and I believe Tony led me down the right path to the solution.

[rwest]

Here’s my thread and it was the red relay- stupid Chinese made one that wasn’t very old either.

Starter continues to run

[Geneman]

thanks very much everyone... this is hugely helpful. i am severly electron flow challenged, in fact, i would rather do a kitchen table prostatectomy.... but i will go out and try,.. tony where is the 14 pin connector, is it part of the ignition switch? thanks again frank

[rwest]

Frank,

14 pin connector is in the driver side back corner of the engine compartment.

Check the fuel pump relay first as it is super easy to swap with the one from the horn- they are both in the front trunk.