I put a dual fan setup on my car. the org. did not work so I thought I found the problem with a broke wire going to the sensor over the starter replaced both wire&sensor. Made sure the fans worked then put them on.Still no fans so i replaced the relay still nothing. The only thing that i haven't replaced new it the sensor on the front of the intake. Had a buddy give me one that he said worked. I can take a hot wire and put it into the wire on the relay that goes to the fan and the fan comes on. Got the other hooked to a flip switch and it works fine. I can un hook the wires on the front of the intake and it boggs the car down. so any IDEAS????

 

anybody ideas???

 

a fan should come on and stay on when the a/c is turned on. I unplugged my compresser because of a sweaky belt when I used my defogger and found out that it needs to be plugged in (a/c compresser) to complete the circuit for the electric fan

 

Does the relay itself see power (constant hot)?

 

The sensor above the starter, between the two rear cyliners on the pass side, thats the fan switch. It should be telling the fan to turn on when it reaches whatever temperature its spec'd for. So if its a 200 degree fan switch then the fan should come on at 200, etc, etc. The sensor at the front of the intake is the coolant temperature sensor, it tells the ECM what temp the coolant is at (which is important because it'll affect what the ECM does). Dont unplug that one its probably not whats causing your problem. Its gotta be something with the fan switch wiring. As far as I know the fan switch is not connected to the ECM, so I think you have a wiring problem somewhere. You proved the fans themselves work, it appears there's a problem with a fan getting signal from the fan switch. If it never worked since you had the car its probably something a previous owner messed with. Hard to troubleshoot. If it becomes too much of a PITA you might wanna consider converting everything to use a manual switch. If you wanna keep the automated setup I think your best bet is to go over Willie's total fan control article with all the wiring diagrams and make sure everything is wired right.

 

well when i had the sensor off i could ground the wire comming off it and it would work. And i havent checked the relay to see if it was staying hot but i will. At this point i'm up for anything. THANKS

 

I thought that was the knock sensor and the temp sensor was on the other side(drivers). could be wrong