I've been trying to solve this mystery for a while now. My Jeep is a 2010 JK Sahara. When I switch the aircon on it takes about 20 to 30 minutes and the fan stops running on speed setting 1. I then switch it to 2, and after about a minute the fan starts blowing properly again until 20 to 30 minutes later when it stops again. The same for speed 3 and 4. If I park the car for about 10 or so minutes the fan works properly until the cycle starts again. This only happens with the aircon on. With the fan on and aircon off or with the heater on this issue doesn't come up. I have replaced the fan resistor and the fan but still have this problem. I must also mention that this is the old style aircon, not the facelifted version with the fancy knobs. Can anyone point me to a possible solution?

 

Do you have a wiring diagram for it? I can peruse that and maybe give you some ideas.

 

Hi,

I have attached the wiring diagrams.

 

This is a very odd problem. If it shut off no matter which mode, I’d reckon something is wrong with the TIPM. My only other stab in the dark is the run relay is opening or fuse M34 is on the edge of being good/failing. Good luck

 

Thanks for trying. Looking at the wiring diagram I'm also beginning to suspect the TIPM

 

The only backyard way to do the diagnosing is how I worked once as a production line troubleshooting electrician. That is to start in the schematic at the wiring source for power and keep going till you find the break. So start at the fan run relay control signal from the TIPM. So ground out terminal 86 on the Fan Run Relay which is the signal for the fan to run from when AC is on. Another issue is to ensure the TIPM is still solidly grounded. Start there and run the AC and see. It's not the fan because you say it runs great with AC off.