In the process of replacing my brake booster, I found that the (apparently) original wiring harness was modified at some point.

I found two wires that were simply cut off in the harness. One is a black wire with an orange stripe that seems to never have power or ground connection. The green wire is hot whenever the ignition is on. I am not very good at reading wiring diagrams, but I can't find either of these wires.

I am attaching a picture of what I am seeing. Both of these are coming out of the bulkhead connector behind the fuse box. On the left of the picture, you can see the brake booster. The thicker purple wire at the top goes to the starter solenoid.

Anyone know what these wires were originally for? Thanks.

 

The black/orange wire is the TH400 kickdown wire that is present in every harness whether you had a TH400 or not. The green wire is the Transmission Controlled Spark wire that also went to the transmission (I ASSUME you are talking about a 1971, since you did not specify year or model).

Both are pretty clearly shown in the wiring diagram in the CSM.

 

Hi Joe - thanks for the reply!

I am trying to figure out where you see this in the CSM? I have the 1971 Oldsmobile Service Manual, but a lot of the wiring diagrams are not well reproduced, like the attachment there.

I also looked in the wiring diagram posted in the electrical forum here:
https://classicoldsmobile.com/forums...d-dfire25.html

That diagram is much, much clearer, but I still can't figure out where you are looking to see those two wires I was talking about.

If you don't mind "teaching a man to fish" could you tell me where to look?

Thanks!

 

This is a 1970, but should be close.

scan0002-1.jpg

 

Your problem is that you have a scan of a CSM, not an original This is why I tell people to only buy original paper copies.

Throw that piece of crap away and get a real one. There are at least a half dozen original 1971 CSMs on ebay at this moment, with prices starting at $10.