Helping a buddy with his 75 280. He's taken the efi off and put on the tripple webers, etc. He says the motor won't shut off with the key. I have read where it needs a diode installed but can't remember where it would go. Anyone onboard that can give us a hand tonight?

Thanks!

Leonard

edit: crane xr3000 fireball ignition

Edited January 6, 201114 yr by IdahoKidd

IIRC, the diode in a 280Z is built into the alternator. Should be no need for a separate diode on that car.

Man that was fast! Thanks for the memory trigger Arne. He has a gm alternator so that makes sense. Newly modified harness so no real clue exactly what he has going on. First time start tonight.

Actually, they used the external regulator up to 1977 (I did the ZX internal regulator alt swap on my 76).

I think the diode is need with the ammeter, which passes current, as opposed to the voltmeter, which doesn't. When did they go to voltmeters?

Either way, I found this link - http://www.zcarcreations.com/howto/voltreg.htm - which says it's the L wire, if you need it.

You can either use a diode on the field wire on the alternator or instead use the charge light/idiot light to prevent run on as a field feed. I looked for an example and found this from a past project. My crude diagram shows both the diode and charge light but only one or the other is neccesary.

I forgot to mention that for a GM alternator, either a "SI" or "CS" type, just substitute the Nissan "L" field connection in my diagram with GMs #1. Also just ignore the jumper bypassing the remote sense. I drew that diagram up for another member creating a bare bones electrical system.

Edited January 6, 201114 yr by geezer

Thanks for the response guys! I am boogered up and can't get out much so was helping over the phone. It appears the crane ignition was fed from a fuse that didn't go off with the key, and thus.........well, it doesn't go off with the key. When I know for sure, I'll pass on the info for closure.