Cooling fan wiring problem
Thread Starter
1st Gear
Joined: Jun 2025
Posts: 1
Likes: 0
Cooling fan wiring problem
Hey im new to owning a C4 and was trying to instal a manual cooling fan switch. Ik your supposed to splice into the green and white but my car does not have that. Ive tried to check further back in the harness and got no luck. any help would be appreciated
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
The computer provides a ground for the relay that runs the fans. You can add a switch to provide that ground (I did on my 1992) to manually turn them on. On the 1992 it will set a code when you do this but it does not turn on the check engine light. I also added a wire to the 12v output side of the relay back to an LED (one for each fan) so I can see when they are on regardless of the turn on source.
