1974 US CSA wiring Diagram

[aeronotix]

Hi,
All the best for 2025: Have plenty of sunny drives with your E9s.
I had a wire melting due to a short and after looking at the spaghetti mess under the dash I'm super confused.
The car was modified from Auto to a 5-speed so I think there are some connectors no longer in use.
I have tried to look for a wiring diagram but I could not find any good resolution one.
Have you guys found a good source to get one?

Thanks,
Stephane

 

[rsporsche]

look in the FAQ - link below. it is in post #20 of that thread

E9 Parts dimensions, drawings, technical info and models

Okay everyone, this thread is the new place to post drawing information, parts dimensions, data, etc. Any of the drawings on this post are only to be used for individual usage and not to be used for commercial profit unless approved to by the individual who created them.

e9coupe.com

 

[Dlc]

you can look into the media section as well: https://e9coupe.com/forum/media/categories/chassis-electrical.49/

 

[Arde]

The auto to 5-speed conversion cabling changes I recall were:
- Remove the gear display indicator and the many cables that feed it.
- Remove while there the seat belt buzzer.
- I think the auto has the neutral safety switch circuit to remove.
- Backup light rewired to the manual transmission.

There may be other stuff if the car is fuel injected...

 

[Ohmess]

Having done this conversion, there is very little electrical work involved. My car did not have a neutral safety switch (although there may be one in your 74), so I merely had to remove the automatic gear display indicator stuff and wire the backup light. Very simple.

I would encourage you to consider other possibilities for your electrical problem. The number one place to start would be any modifications to the radio/stereo. This was the single biggest problem with my car when I bought it. https://e9coupe.com/forum/threads/rear-light-dilemma.42792/post-375463.

I learned when doing all of this (and from Mario Langston at VSR), that wiring melts at the ends where the resistance is highest. So if you have found a melted wire, you need to trace that wire and check the other end. I found several melted on both ends.

 

[aeronotix]

Thank you all for your answers.
In fact I would like to simplify the wiring by removing all the automatic related option.
Then go thru a complete inspection of the burnt wiring. I have found the short so everything from this point to the fuse box.

 

[Breiti]

That is, how the inside harness looks like.

There round connector keep for the backup light.

Breiti