I have a 1987 IROC with 350 tpi and all stock motor with dual electric fans. The fans worked yesterday as they should. The primary would come on with the a/c on and at 230 degrees again the fan would go on. So I taped in the green/white wire on the fan relay connector to put in the hayden 3652 controller and now none of my fans work at all even with the ac on. I measured the outputs on the fan relay connector and the orange-12v, tan/white-12v, and the other 2 wires is getting 0v when the car in keyed on but not running. I think this is normal voltages I believe. I am thinking the fan relay is not working?? Any suggetions? How would taping into the fan relay connector cause my relay not to work??

 

http://www.haydenauto.com/Upload/Hay...ontrollers.pdf

Your not supposed to use the factory wiring/relay - your saupposed to completely start new with wiring for this fan controller - the only factory wiring used for this setup is the actual wires to the fans.

Your factory wiring/relay isn't going to get power until the ECM sends the activation signal to the relay - so your connecting a fan controller to operate AFTER the ECM operates the fan anyway. Just follow the directions above and remove the factory wiring/relay.

 

Well, I thought the problem was tapping into the relay but really its the a/c system. The a/c hasn't been used in a while and so I charged the system and it seemed to working ok. When the a/c was on the primary fan was operating as it should. I turned the car off and waited about 5 minutes and turned the car back on and the a/c is blowing warm air and the cooling fans are not operating now even when the motor gets up to temperature. When I measure the voltage on the relay connector with the car off I get 12v on the orange, which is hot at all times and 0v on the rest of them. When I turn the key on without starting the car the voltage on the relay connector is 12v orange, 12v tan/white, 0v green/white and 0v black/red wire. When I put the relay back in the green/white wire will have 12v. I think this is correct voltages. Is there something in the A/C system that overpressured and is disabling the cooling fans? Help would be great.

 

The A/C switch works from pressure - if there's no pressure, then the switch won't activate, thus the wires from the controller that you have tapped into the A/C wires aren't getting any signal. I'd recommend (since the A/C isn't working, and thus no pressure, and thus no switching) to just skip the A/C function all together, and let the controller simply run the fans based on temps alone.