Whoever had the car before my rigged the fan so that it comes on all the time. I correctly re-wired it back to the '86 wiring diagram's specs, but now the fan won't come on at all. The fan fuse is fine. The fan motor is fine (it worked while jimmy-rigged). The fan relay is fine....i bought a new one and it still doesn't work. What else could it be? When exactly is the fan supposed to come on?

 

I just went out to the car with a test light, stuck it in the relay where the green/white wire goes in, it lighted up, and the fan started up. I don't know if this means anything or not...but it now seems the relay and fan are definitely fine.

 

I've been reading other posts and it looks like this all means the fan switch might be bad? Do '86 IROC's have a fan switch?

 

I believe it's got a temp switch, or something. If you check the tech articles, there's one for rigging the secondary (?) to come on manually, by a switch in the car. That explains it all al little better...

 

According to my diagrams the 86 uses the ECM for fan control, there is no fan switch per se. The ECM using information from the coolant temp sensor controls fan cycling. Don't forget that the fan will not come on until somewhere between 220-230 degrees coolant temp. That was designed intentionally so that the fan won't constantly cycle shortening it's life as well as placing stress on the alternator. You will see a lot of discussion about manual fan switches, different temp fan switches(if so equipped) and the like. None of it is worth the time and effort. If the cooling system is operating properly and your airdam is intact your engine will operate in the range it was designed for. Also a bad CTS will trigger an SES light. Don't overlook a dirty or corroded fan relay plug.