So just put in a new radiator, hoses and thermostat. And after letting it hit 190, confirmed with a laser thermometer, my electric fan didn't kick on. I turned on the ac and defrost and nothing. What do I test and how. It's a 88 XJ 4.0 auto with the factory tow package, two radiator coolers.

 

You have one mechanical fan and one electrical fan?

If so the electric fan turn on with the a/c and or when the temps hit 218.

(at least for my 1999)

 

Test the electric fan and put power to it. If it works plug it back on and run the jeep for 30 minutes and see if kicks on. You can also make the fan come on constantly with your ignition. You can also put a toggle switch for it and control when it comes on. Just make sure you place the switch somewhere above your knees.

 

Anyone know why my electric fan clicks on and off at very regular 10 second intervals when idling? It got so annoying I disconnected it, but I would like to get to the bottom of the problem.

 

It's a helluva lot easier to help someone when they include at a bare minimum the year of their Jeep in their post or at least have filled out their profile.

 

There's a relay for the electric fan not far from the plug. It could be bad or missing.

 

in the next thread, we'll be reading how come it's overheating...
[sarcasm]

 

mine does that, plug your's back in.

The details on the JEEP.
year make model?

 

One reason for rapid efan on/off is a/c system is low on refrigerant.....the efan really needs to be plugged in.

 

I'll join the fray, but not looking to fight - only help. I've got a bone stock 99 Cherokee Sport XJ 4x4 with A/C. When I first got it, the e fan would cycle on and off during idle, and come one when the temp got above 218 and A/C on. It seized up on me, & I've replaced with one from a 2001- same make, model, etc., & still won't work. With A/C on and temp reads 220 - nothing. Then the temp shoots right to the red line. Driving with A/C there isn't an issue of overheating. Only at idle. Then there's a beep followed with check gauge light coming on. Not being a mechanic, is there a way to test the e fan other than at idle and with A/C on and correct temp is reached? My neighbor (a mechanic/jack of all trades) and I tested the relay's and fuses in the pdc, and the 10 amp fuse inside on the passenger side. Fuses good, not blown, and relays swapped around to determine if A/C relay was bad. It's been replaced. Hooked wire from battery to fan plug and it did turn. He feels the temp sending unit is probably bad. Each time I thought about attempting to replacing the unit, the engine was hot. This weekend I'll back it in the garage, and replace the unit while the engine is cold. Before replacing the unit, is there one further test that can be done, that hasn't been done? Since I have sub par mechanical abilities, I'm asking those who have been here before. I hesitate big time going to the stealership, as they will gouge me for every nickle and dime I have. Sound assistance and advice please. Guesses can't help at this point. Thanks.

apw

 

What cooling system maintenance has been done? Which list is shorter, what has been replaced or what hasn't been replaced?

 

So far I have replaced the radiator, all hoses, and the thermostat. It is running great and isn't overheating at all, but I have to take it on a 8 hour drive in a couple of weeks to southern Oregon and I don't want to have any issues on the drive. I didn't get a chance to hook direct power to the fan yet. But when I turn on the ac it blows cold and the fan doesn't kick on, so I'm pretty sure that the fan and or relay is toast. I can get a used fan for 20 bucks so I'm going to go ahead and get it and see if it works. If not I will get the regulator.