two red wires in engine harness

[fasterlaster]

I'm going through and cleaning up the wiring loom mess in my 74, and have run across something that I can't find in any schematics to back it up. A few things to make it more interesting:

• It has a 3.2 DME engine complete with FI parts
• The engine harness with the 14 pin connector has two same size red wires.
• Both of these wires test for connectivity, but I haven't pull the alternator to see if they are both attached on the alternator.
• One red wire feeds the rear window defroster relay
• The other red wire feeds into pin #2 on the engine 14 pin connector, then on to the 'spare' green wire that runs to the front of the car and is not connected. (apparently this was for a sportomatic trans temp sender and not applicable on my model)

The questionable red wire is in engine harness itself, and looks stock, that is the same type of wire. It runs just fine with this odd layout, so I'm not real inclined to fix what ain't broke. Just wondering if anyone knows what this red wire is.

[timmy2]

Red wire from pin 2 of 14 pin connector should run directly to the alternator in the engine harness.
Where is the other red wire
in the engine harness connected in the 14 pin connector?

[fasterlaster]

Red wire A is connected to #2 pin on the engine side of the 14 pin connector. It passes to a green wire that also goes to #2 on the chassis wiring schematic, and up to the front (not connected)

Red wire B is connected to pin #12 on the engine side of the 14 pin connector. It passes onto fuse #3 of the rear fuse block and then onto the defroster relay.

[timmy2]

Ok, that is more clear.
I just looked and the '84-'86 harness I have for cloning new ones. It has 2 red wires in the 14 pin connector to terminals 2 and 14, number 12 is not used.
Both go directly to the alternator positive terminal.
The conversion in your car would have changed the need and purpose for the wires at the 14 pin connector.
If the car is working right then I wouldn't worry too much. If there is no terminal in pin 14 then they moved the red to suit the '74 chassis wiring.
I'd have to look at the schematics to confirm but if it is working..... Why bother?
Is there a wire in terminal 14 of the engine harness?

[fasterlaster]

Thanks Timmy, my thought as well was to just let it be, and I had a typo above it's actually terminal 14 not 12, so it sounds like the harness is exactly as expected compared to what you have. Thanks to your tip I looked at the Haynes diagrams and found it does show 2 2.5mm wires to the fuse box #3. I think it's all bridged based on the dark line below, but the #135 is a connection rail, so at the very least fuse 2 & 3 are bridged together. I'm just not entirely sure I'm reading it correctly.

either way, at least I feel comfortable that the harness wiring hasn't been monkeyed with. thanks.

[timmy2]

You are correct, 2&3 are connected. Happy to help where I can

[E Sully]

Porsche used parallel feeds for that situation. The wiring diagram states one to fuse 2 and one to fuse 3, but does show them bridged at the fuse block. The second load on the system was for the later Carreras Blower Control Unit, so it is no problem eliminating it on the early car since that load does not exist. I eliminated the pin on mine, I did not want power going through the non fused Green wire causing any problems later.