I installed a LS1 in my 80 vette. Had a shop make me a harness for the setup. The only thing they forgot to hook hook up was turning the fans on when the a/c is turned on. I talked to them long time ago and they said I just needed to connect some wires and to bring it in. However, the car stayed on jackstands for the past year while I have been modifying the rest of the car. Now the guy who built my harness has moved on to bigger and better things so I have no contact with him.

Anyone know what wires they are talking about it or how to turn on fans with A/C?

 

Bump....

 

In order for the LS1 ecu to control fans with AC request seems to require the pressure sensor from the LS1 car be grafted in the system. My suggestion would be to replace the binary switch with a trinary to control the fan as well as the compressor. I did that on both my LS swaps, works great. The other option would be to turn the fans on any time the AC is on. You could find the connection for that at the binary switch.