Hey guys, so my friend just got his 160' fan switch installed on his 91 Z28 and for some reason the fans won't come on at the lower temp and will only come on on their stndard temp which is 225. Any ideas why??

 

The new fan switch should only cause the passenger side fan to come on earlier. If they are both coming on together someone has wired them together to come on from the computer possibly because of a previous fan switch failure.The wire from the fan switch should lead to the relay for the secondary fan and that fan should be powered by a wire from that relay. Grounding that wire with the key on should activate that fan. If not the relay is bad or somebody rewired something.Go backwards from the fan to see where it's power is coming from, that may tell you what's going on? Check out the article in the technical articles section describing how the fans are supposed to be set up. That may help if you don't have access to a wiring diagram. Have fun!

 

Thanks buddy!! I didn't even think about looking at the relay. I will check with my friend, will see what we come up with.