I have a 71 cutlass S 455 automatic. It’s a heat and A/C car. There is a new wiring harness that wasn’t finished. I can’t add a picture right now but I can in a week. I see a black wire that is the ground into the firewall. A green wire that runs to a relay with a blue, orange, and black wire. When I turn the switch on for the fan to run, nothing happens. Does anyone have a wiring diagram or troubleshooting tips? Thanks in advance!

 

Electrical Forum
1971 Original GM Oldsmobile CSM Wiring Diagram A Body "V-8"

 

Thinking about this, I believe the blower wiring harness was installed by Fisher; albeit, I think the wiring diagram (harness) is contained in the Fisher Body Service Manual. I'm busy at the moment, I'll see if I can find anything if/when I do I'll post.

 

The wiring diagram for the factory HVAC is in Section 1 of the CSM. The wiring diagram in Section 12 only shows the base equipment harness. It does not include options like A/C or rally pac.

 

Oh, that's right. Thanks, Joe.

 

I've found the wiring diagram in Section 1 of the CSM (as Joe mentioned) to be simple, concise and well displayed.

 

You guys are awesome. Thanks a lot. Hopefully I’ll have it working soon