Alternator wiring
 

I am replacing alternator and voltage regulator in my 74 911 with a Bosch alternator with built in regulator. I’m fairly certain I know where to hook the hot red wire and blue wire that goes to the instrument panel. I cut and capped the black voltage regulator wire. I’m not sure what to do with a white or faded tan wire that remains. I took pictures of the original wiring but they’re not helping me. I’d appreciate any help I can get.

Ron from Indiana

"Tan" should be brown. That's the ground wire. It doesn't do anything with the VR removed, but I would ground it to any convenient nut/bolt/screw.

Thanks for your help. If I understand correctly the only important connections are red to B+ and blue to D+. Not sure but I also take brown to any place I can use for ground. Wiring diagram says D- but maybe that’s not necessary.

When you say ground it to any nut bolt screw are you saying any nut bolt screw on the alternator or somewhere else close to the alternator?

Either the case of the alternator or a stud/nut/bolt on the engine.

Thanks again.