74 electrical mystery on the engine panel (big pic)

[Pat S]

Okay, I have a 74 911 (not s, just regular)
The car ran fine except for the cold start function but had some pulled headstuds and oil leaks so I'm in a rebuild right now.
I decided to pull off the electrical panel (not sure what it is really called) to clean it up and found some new issues.



So I've got two questions.
1) What are those 2 blue wires and 1 black wire for? They were taped off and tucked in a hole. They go back into the small harness

2) The fuse box is upside down. This seems like a big problem because posts 1 and 2 are connected on the back.
-So in the config now, I'm guessing that means that current flows from right to left, from the bottom right wire across the bottom fuse then into both bottom and middle left wire. This leaves the middle fuse useless.
-From what I can read in the current flow diagrams I have, it looks like the wires are all in the correct place and that I just need to rotate the fuse box to make everything right again.
But the big issue is, it was running fine before I started, so should I change yet another thing in the middle of a rebuild?
Also, what the heck are these for?? the manual says 1 is sportomatic (don't have), 2 is starting valve for carrera only (just a 911 regular) and 3 is rear window defrost. If that is really the case then the only one that I really should have is 3 and it probably doesn't matter at all what I do.

Thanks,
Pat

[Jim Sims]

The two blue wires and one black wire went to the external voltage regulator; it is likely your engine received a new alternator that contained an "internal" voltage regulator (actually mounted on the back of the alternator). The external voltage regulator was removed and the wire ends taped so they wouldn't short.

The fuse block is correctly mounted as shown in your photograph and the only fuse needed for your car is #3 (the top one) if you want the rear window defroster to work.

Cheers, Jim

[Pat S]

Outstanding!
I do have an updated alternator.
Thanks Jim.

[azasadny]

Jim,

Thanks, I had the same question and you answered it.