Hi have a strange problem with the e fan on this 2000 cherokee classic 4.0 auto.. The truck has 174,000 miles on it I picked it up for my niece and have been going over it for the last week.. I bought it as a good runner and it does run well and is also pretty quiet.. My question is I will start the truck cold it takes about 15 min. to get to temp?? about 200..After about 20 min of sitting the fan kicks on but does not seem to shut off?? The temp. is normal or below I am guessing about 215 below the center mark on the dash. Not running hot plenty 0f power no miss no pinging no check engine light all seems fine I had replaced the valve cover gasket and their is no sign of coolant in the oil , looks as it should and pretty clean.. You can tell the oil was changed regularey.. If I shut off the truck and then restart it while still at same temp. the fan does not come on for at least 15 min., at idle?? Really does not seem to be running hot I know it has the famous 0331 head but do not see any evidence of overheating or crack between 3&4 cyl head>. I also tried swapping the relay and same results?? Am I looking to close?? Just want to make sure it is good before I give it to my niece .. Thanks, Bill

 

Honestly I wouldn't worry about it. Do a good drain, flush fill on the antifreeze and drive the wheels off of it. The center mark is 210 but that gauge isn't always 100% accurate. If it's anything it's probably the sensor in the thermostat housing being slow to react. That's what tells the fan to turn on and off. If you decide to replace it go get a MOPAR unit. Also check and make sure it kicks on with the AC clutch as well. I believe yours is a good problem to have most of us deal with the fan not running at all rather than more than what we think it should.

 

On later Cherokee's, the electric fan is dependent on engine temperature. The electronic fan does not cycle with the A/C clutch.

 

Thanks the fan does go on when I put the a/c on.. I did flush the entire system then installed a quality water pump thermostat and gasket all new hoses flushed the heater core and put new hoses to it.. I even bought a new coolant tank everything is clean and really was before, The p/o seemed pretty honest and said he never had a problem he did change the oil every 3,000 miles and had pretty decent records,... I will change out that switch and see what happens..

 

That's not exactly correct........'00-'01 XJ efans cycle on at X coolant temp AND X a/c line pressure. Obviously, when a/c line pressure has reached X, the a/c clutch has been engaged and cycling. A/C line pressure can easily be high enough to turn the efan on well before coolant temp is high enough to turn the efan on.

 

The electric cooling fan comes on when the engine temp reaches 218 degrees, or when the A/C head pressure reaches around 430 psi on the 2000-01 Cherokees.

 

Hard wire it. It was easier than figuring out what went wrong. Now I switch it on and off as needed.

 

Really??????........that's a band-aid at best and not really a good idea/suggestion for someone that's trying to diagnose a possible problem. Does your temp gauge tell u when coolant temp has reached 218F? Where is 218 on the gauge anyhow? Does your a/c have a pressure gauge to remind u to turn on the efan? to the fan switch idea unless u frequently drive off into high water.

 

Thanks for the addition.. the point I was trying to make was that just because the clutch is engaged doesn't mean the e-fan will be running (like it may on some vehicles).

 

Now the statement is totally correct, for '00-'01 XJs. '99 down, the efan is turned on when the compressor/clutch engages and/or coolant temp reaches 218F.

 

for 2000, the efan comes on at 223º or when the a/c cycles.

 

'00-'01 efan on at 223F.......good info to know.

"A/C cycles" is the clutch engaging/disengaging. '00-'01 a/c systems can "cycle on" and the efan NOT turn on, because the pressure may not be high enough to turn the efan on. '99 down efans turn on when the clutch engages, regardless of a/c line pressure.

 

Yep the 00-01 is a little different beast. I wish the efan was always on with the a/c.

I want to wire up a toggle for it, just have to search for a how to.

 

Go here and read through post #42. 00/01 AC system pressure switches.

https://www.cherokeeforum.com/f2/gre...e-6558/index3/

 

Thanks Ken,
So if I read that right, I can take #2 wire of the A/C high pressure switch, apply ground to that wire and the e-fan will come on. Does that sound right to you?