Matt21

I have a 96 Cherokee, The acc fan doesnt turn on until the jeep is running close to 260 degrees, I replaced the coolant temp sensor on the goose neck, the temp sensor on the head and a new clutch fan i checked all the relays and fuses and they are all good. I have also put in a new computer as well. Now here is the funny thing the coolant temp sensor on the goose neck is for a 98+ i believe because for some reason Idk, but when i unplug it the fan kicks on and stays on. can anyone explain to me whats happening? And how i can return the fan to kick on at the right temp?

Unknown XJ

From what I've read there's a temperature sensor for the fan itself..... look around behind the drivers side headlight in the engine compartment..... I think that's where it's at.
In regards to the fan running after you unplug the temperature sensor on your goose neck,the ecu isn't receiving a signal from said sensor. Think of it as a fail safe. Someone correct me if I'm wrong please. I'm always interested in expanding my knowledge base.

djb383

The coolant temp sensor in the t-stat cover signals the ECU to turn the efan on at +/-218F. Unplugging the cts is the default fan on signal and sets a CEL. Verify coolant temp with a infrared temp gun pointed at the t-stat cover. If efan comes on at +/-218, gauge is whacked, if not on at 218, something electrical somewhere is whacked.

Unknown XJ

^^^^^^ Listen to this guy he knows his way around!