Thanks, I'll try this. I do have a multimeter. Just confirming, grey wire is hooked up to battery, black wire is always grounded? And what do you mean by the blue/yellow stripe?Do you have aMultometer? You Will need one.Make sure you have the key on for these test's too.
1. Unplug the Fan motor
2. find a Way to Tempoarily Ground the ECT Sensor, you can use a small peice of wire
3. At tthe Fan plug connector you will See a Black and a Gray wire.
4. Using a multimeter you should have 12V DC at the Gray wire while the ECT Sensor (Make sure the Yellow/Blue Stripe is grounded)
5. Test the Fan ground, Black wire should have continuity to Ground (Multimeter should beep) which shows you have good ground.
If all that checks out to be good you just need a new Fan Motor.
Where does the ground wire go toI had a problem with mine ever since I had bought the quad it never came on. Didn't think much of it but after my motor rebuild I wanted to make sure it worked. I had the same issue red light would turn on but fan would not turn on. Went through and checked all connections and back probed my harness and ecu. I jumper wired my fan to work from the plug and then plugged it back in to see if anything was coming from my ecu to the fan and nothing. I did have power to the fan just no ground. So figured the ground was bad through the ecu, and by passed it and put it on a switch which I had already planned on doing anyways.
On the fan side of the Connector, there is Green and a Blue wire. As you said you discoverd that the Fan is in fact working (that is good now we can back track the wiring of the Quad)Where is the ground wire for the fan in the ecu