Cooling Fan
 

My 01 XJ runs cool when sitting. Runs a little warm driving it. Cooling Fan never comes on. Relay replaced, fan will run when I unplug it and put power to it from 6 amp battery charger. Any ideas?

check the wires running to it. my ground was corroded and wouldnt make it turn on.

Similar thing happened to me. The factory connector fell apart. If you unplug the coolant temp sensor the fan should turn on you can check for voltage at the connector. That'll rule out anything from the connector to the relay.

Are you sure?

Unlike the '99 and earlier XJs, the electric fans in the 2000 and 2001 XJs come on under two conditions:

1. The fan comes ON when the coolant temperature reaches 223° F and goes OFF when the coolant temp drops to 217° F. (Earlier XJs kicked on at 218° IIRC.)

2. The fan comes on when the high side of the A/C system reaches 300 to 320 psi and goes off when it drops to 235 psi. The fan does NOT come on automatically when you turn on the A/C like it did in earlier years.

A lot of people with '00-'01 XJs think their fan isn't working because they never see it come on, when the reality is that they haven't met either of the conditions for it to come on. So, with all that said, are you SURE your fan isn't working the way it's supposed to?

Cooling fan never comes on
 

Well, now I have doubts that it is not working properly, you have given me reason to rethink this issue. Let me ask a couple other questions(which lead me to think fan isn't working):
When Jeep is sitting(in drive way) engine temp is fine, when I drive it temp raises to 10-15* above normal. Do you think this is caused by restricted air flow with winch in front of the grill. Yet, the engine isn't getting hot enough for the fan to come on.

What are you considering "normal"? This motor runs pretty hot. If it's not getting above 220° or so, it's not really running hot. You can't always trust the gauge on the dash. You can confirm your coolant temp with an IR thermometer pointed at your thermostat cover.

When you remove the radiator cap (while the engine is cold), what color is your coolant? Is there any brown gunk there?

Have you done any cooling system maintenance recently? If you are really running hot, it might be time for an overhaul: radiator, hoses, water pump, thermostat, radiator cap and a flush. I also include the fan clutch when I do this, since there's no better time to change it than when the radiator is out of the way.

Does it come on when you unplug the coolant temp sensor? If it doesn't it's wiring. Otherwise check temps with an IR gun.