Fan relay wires
Red - Fused 10 amp unswitched fan power supply
Yellow/Black - Fan "on " Command ground is supplied by the ECU , closing the relay to turn on the fan
Red/White - Key On battery power supply , switched on by key and LH control switches , enables power to relay
Orange/Black - Fan battery power supply , switched on by the ECU , enables power to fan .

Plug pattern looks like a cross

 

Trace back from the relays along the harness and you should find a thermal fuse supplying power to the fan relay. We just had a new Ranger doing the same thing,no fan! Turned out the thermal fuse was bad not allowing power to the relay. Hope this helps? OPT

 

Thanks for help all. Been tied up with work, hope to get back to this project tomorrow night. Will update all with what I find.

Ken

 

OK, I have busted knuckles and about to pull my hair out, but still NO FAN.

Red, Red/white, and yellow black wires to relay have 12 v with key on. Relay is good, tested on bench. Found thermal fuse on frame, it is good, tested on bench...

Orange/black, with key on or off, has 0 voltage. The orange/black should feed the power to the fan I think. The plug to the fan has orange/black and black on the plug, but no voltage to either... I have not stripped the wiring completely from the plastic over cover.

When I unplug the temp sensor wire, nothing changes. From what I am reading about a fail safe sensor, if I unplug it, the yellow/black should go to ground, and send power thru the orange/black to the fan... right?

What next? What am I missing?

thanks all!
Ken

 

Has anyone ever seen part of an ecu go out?

Bike starts and runs fine. Fan just does not work.

thanks

 

No ECM recall on a 2008,did you do a direct 12v dc jump to your fan to see if its shot?

 

ECU supplies ground to complete the circuit and yes,portions of a ECU can go bad.

 

Wanted to update everyone, and thank everyone. OPT, once again - as usual, you were on the money. The thermal relay was bad. Just testing with a meter it showed fine, but once you put a load on it, it would go open... never been so happy to give the autoparts store $5.

Also, when testing the circuit, to see if the fan works in fail mode, you must crank the engine... I would pull lead off of the temp switch on the cylinder, thinking that with key on it would cause fan to run... you actually have to have the engine running, and give it a couple of seconds running, to see if it works or not.

After pulling a wire out of the bottom of the fuel pump relay by accident, and taking another night to find that, I finally have by ATV running again. (in time for hunting season!)

thank you all

Ken

 

I have a 2006 and it was reading HOT on the dash board, when we knew the quad was not running hot. What my problem was is an electrical part that goes above the rad, it was about a $300 part, and a couple hours of labor, probably pretty easy to change. When I took it in I had no idea what it was. Hopefully this helps.

 

What part was it? If it was an ecm should have been under warranty?? What 2006 model do you have??