Hi, recently sitting on an interstate in traffic my car overheated. I diagnosed it as the radiator fan not spinning. I tested the fan, it was dead, so i replaced. The fan still will not turn on though, i checked the wiring from the relay to the fan, and a wire was burned out, i repaired the wire thinking i found the problem, still no luck. I replaced the relay, still did not correct the problem. I ofcourse have checked all fuses, and even replaced the one that corresponds to the rad fan and other components, and still no luck. The only thing I can think of now is it could be the temperature sensor? The engine temp is gettign recorded fine on my cluster. Would the same temp sensor cause the readout on my cluster + control when the fan turns on, or would that be two different sensors? If i cant figure it out, my only other option i suppose is to wire a switch into the car to manually turn on the fan, but I want to try and avoid that. Thanks for input

 

the temp sender for the fan is seperate from the gauge and is in the right head.

------------------
ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

There are four wires going into your coolant fan relay. Don't quote me on the colors but heres my shot:

Orange (Load to fan)
Black with red trace (+12v feed)
tan? (+12v to coil side of relay w/ KO)
green with white trace (ECM ground if primary fan)

Take the relay out of the connector, and jump the terminals that correspond to the heavy gauge wires. (orange and black) If the fan doesn't run, you have a bad fan, bad fuse link by starter, or bad wiring to fan itself. If it doesn't run, check the coil side of the relay by probing the green/white wire and tan wire with a DMM. Put the ECM in field service mode and note DMM. Should be 12V. If no voltage is present, probe tan wire and good ground. If 12V is present, check green/white wire back to ECM, could be open. If no +12V @ tan wire with KO, check fuse and trace wire back to ign. switch.

------------------
-Jason M. 1991 Camaro Z28

 

I can think of one thing it might be..... FANSWITCH

We had the exact same problem as you are having.
Fan died...and took along a couple of other things as well.

Had to replace the fusable link and the fan switch.

Check to see if your fuseable link is fried. It's located right next to the radiator by the battery. Check those wires to see if they are fried.

If everything looks good there then go under the car on the pass side bt the starter. Look up in between cyl 6 and 8 and you'll see a plug going into the engine. That's the fanswitch. Ours was fried to a crisp maybe yours fried as well.

A couple of tests you can also run.

1) turn on the car and start the A/C the fan should be running no matter what the temp of the engine is.

2) The fan will NOT come on unless the engine is @ 220°. Only exceptions are if you have the A/C on or if you have a fanswitch that is set to a lower temp.

Try these couple of things and you might find your problem.