G`Day guys, i have a 2002 TJ exec 3.5l and the thermo fan wont cycle, it comes on at runing temp (half guage) and wont turn off. The car dosent move from half temp even in peek hour traffic. but the fan just stays on. any ideas about this would be great guys.

Thanx Ziek

Is there anything restricting air flow through the radiator? (bent fins, or dead bugs)
Is the coolant in good condition and at full level?
Does it happen with a/c on or off, or both?

When I have my a/c on, one of the fans runs continuously (when temp in halfway) and only every now and then both fans may stop if engine has been iding for at least 2 mins (or 3-4 a/c fan cycles).
I rarely drive with my a/c off so I'll try and pay attention to it next time I drive it to compare.

any lights on the dash when it does this?

as i know that mine will default fans on, when the sensor is unplugged. or weirder airpockets in the system

Thanks for the replys guys, aircon don't work unfortunately, when I turn on the switch to the aircon the aircon fan comes on. No lights come on the dash, so no fault codes come up. There is no coolant in the system, it's a job I'm going to do tomorrow. Radiator is newish from the looks of things, no bugs or bent fins. When the car cools down the thermo fan didn't come on again till half temp, then just stays on

problem solved, after using coolant in my system, (remember i just bought this car so havent checked every little thing out) all i used was concentrate coolant for like $6. and many thanks to both replys, between the 2, i found the problem