Recreating Alternator Wiring from Poor Records

[OsoMoore]

The current owner didn't take sufficient photos when they disassembled the fan assembly, as a result that owner is scratching my head at how to put it back together properly.

The incoming wires:
1) Paired thick red wires
2) Tripled smaller orange wires
3) Single blue wire
4a and 4b) Red jumper wire, pretty long

There are 3 contacts that were used:
A, B, and C on the lower left, top left, and bottom right edges.

The photos I did take show:
A) 4a and 2.
B) ??? but pretty sure 3
C) 1

Not sure where the other end of the jumper (4b) goes. The wire is long enough it could be anywhere.

Current photos of wires and connections, followed by the 2 photos I do have when when the current owner (uh... me) took it apart.






Yes, I know I'm an idiot for not taking better pictures.

[OsoMoore]

This thread's "old alternator" diagram seems to match mine. But doesn't say anything about where the jumper wire goes: https://forums.pelicanparts.com/porsche-911-technical-forum/401341-alternator-wiring-advice.html

Looks like the jumper goes to Ground... somewhere? The housing?

[wazzz]

The big jumper isn't red but brown. It is the main ground wire that goes to one of the case nuts that ties the two engine halves together, on top of the engine block. Can't remember which, but I think it is the first nut at front of engine.

Edit: found a pic of my long block. Took a screenshot. This is the third nut starting from the rear of alternator.

[OsoMoore]

Thanks, you're a lifesaver for... uh... current owner! I guess that explains why I didn't have a photo - it came off the block a couple months ago.

I can correct that wire even though I've now put on the shroud, as there is room to work inside.

[wazzz]

You should change this wire anyway. It appears toast. It's a bit less critical on a CIS, but on a 3.2 with Motronic, it can leave you stranded, pun intended

[spoke]

Originally Posted by wazzz

You should change this wire anyway. It appears toast. It's a bit less critical on a CIS, but on a 3.2 with Motronic, it can leave you stranded, pun intended

100% agree. The OEM ground wire from the alternator to the case is tiny. The one provided on the WOSP 175A alternator is huge. All the electrical current in the vehicle flows through that ground wire.

Your wire shows fatigue. Definitely replace it.