Tactical_Geek

So it worked yesterday and now today it doesn't. Nothing changed, didn't go mudding. I only noticed it because my AC wouldn't work when I was sitting still so I thought, hmm, I need to recharge it. Nope. When I got home I left my Jeep running to check on the compressor and noticed the fan wasn't running... at all.

So I turned it off and on and then let it sit and idle. It got up to about 220-230 and it never turned on. I checked the fuse and relay and both seem okay. Are there any tests I can use to see if the fan motor is still good?

Radiator is good and clear.

Mr.T

Take a couple straight pins or needles from the sewing kit and push the pointy end through the insulation to the copper on both wires leading to the fan motor. Attach a volt meter to the pins. Voltage yes and fan not turning = bad fan motor. And if the fan is good, smear some silicone gasket maker on the pin holes made in the insulation when the troubleshooting is finished.

rob_engineer

Mine stopped working when my battery connector came loose. Tightened it up. Problem solved. There some wire connected to the battery terminal that goes to a part near the radiator.

Tactical_Geek

Thanks for the tips guys. I'll look into it further tomorrow as it's dark out now.

Tactical_Geek

Just disconnected the fan plug and tested with a voltmeter. It's got 14v at the fan connector with the AC on. Would this indicate an issue with the fan itself?

karls10jk

What's the price on a fan? I've got an extra fan motor that I bought and hadn't used that I could send your way for a nominal amount. It's a used motor but I was having a noisy fan issue solved by a little silicone squirt in the center.

Mr.T

It probably is, but if you use the pins in the wires and measure it (essentially under load) you will know for sure. A high resistance somewhere (like a contact or connector) will show voltage (at the connector in this case), but under actual load the voltage drops to near zero.

RubiKean

2008, right? While you have your meter out.... there should be a green voltage divider near the fan harness on the fan. Inspect that guy... and meter downstream of the divider. Chances are that either the fan just died or that voltage divider crumbled to its natural elements.
It's a bit of work, but you can pull the whole fan and test it the motor itself. The motor has a plug to remove the 2 wire harness that runs up to the voltage divider.
If you have to replace the motor, it's really not a big deal. The design of the motor exposes it to all the road and off road crud... it's not unusual for the 07-11 fans to die.
-Chris

Tactical_Geek

Yes, it's a 2008. I tested down on the fan plug itself. I'll check out the voltage divider.

Tactical_Geek

I tested the voltage divider which came back good. Put 12 volts on the fan itself and it did nothing. Got a new fan on the way. If it doesn't work I'll start looking more closely at the relay, associated wiring and what not.