Elec rabbit hole

[LuvNH]

Afternoon all!

1979 911 SC have had it just under a year and am working through various things.

Currently working on an alternator that won’t charge. Red dash light on during start, rev engine and it goes out. I jumped out after I started it to check voltage and briefly saw 13.2 then quickly dropped to ~12.5v across the battery. After 20 min of driving, seeing 11.2 or so. Been reading all the other forums and am working through grounds, and the flat pin on the starter is a bit loose.

This lead me to the rabbit hole(s). See the pic below for a green wire inside back insulation in the back right of Eng compartment. It was cut back by the tail light connector and it runs along the sidewall behind the RR strut mount down into a sleeve that runs into the pax tub. I’ll open the shift linkage cover to see if that sheds any light.

Also, other pic- does the lack of connection on the VR mean that I have the newer alternator with the internal VR? Or can this be the source of my problems?

Also, note that there is no wire connected to the rear side of fuse #3? There was a fuse in there, but I removed it bc there was no wire there.

Where in the %#$&@ is GR#1? I found and cleaned 4, but no luck on 1. I see one clear on the right side of the car near that mysterious wire with nothing attached. Looks totally clean.

Ideas?

[wazzz]

Originally Posted by LuvNH

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Also, note that there is no wire connected to the rear side of fuse #3? There was a fuse in there, but I removed it bc there was no wire there.

Fuse block terminals 2 and 3 are electrically tied together by an internal blade that you cannot see. So the circuit is completed and power is fed from terminal 2 to terminal 3. You should put this fuse back, it is useful.

[blucille]

First pic is likely the wire that would connect to the air conditioning compressor, if you had one.

[LuvNH]

Originally Posted by blucille

First pic is likely the wire that would connect to the air conditioning compressor, if you had one.

Aha! That would explain it. There was one, PO was doing something, not sure if he was upgrading or deleting. I have all parts for it. On the list…

[LuvNH]

Originally Posted by wazzz

Fuse block terminals 2 and 3 are electrically tied together by an internal blade that you cannot see. So the circuit is completed and power is fed from terminal 2 to terminal 3. You should put this fuse back, it is useful.

Ok, sure thing, will do. Many thanks for the help.

Love this site.