I have a 2001 xj and my AC is blowing warm. The compressor is cycling and the axillary electric fan is not spinning when ac is on. The compressor cycles every 6-8 seconds. When i unplug the temp sending unit the fan comes on full and i get moderately cold air out of the vents. On some occasions the clutch will not engage. Its is very hot in Alberta in the summer and i cannot take my son in this during the summer any help would be appreciated. AC charge is good.

 

Perhaps your Low Pressure Cutoff switch is defective. Under normal circumstances, the LPCO switch would cause compressor cycling with no e-fan operation (as-described) but only if the condition were true. Jumpering the connector through the back side where the wires enter would be a simple test because it would make your compressor and e-fan run while the jumper is present and you could have someone check for chilled air blowing out of the vents (or you could check yourself). I'm not sure if there's a High Pressure Cutoff switch - maybe someone can chime in on that - but unless you know for certain that there isn't another cause for your situation I would not recommend keeping the jumper in the LPCO. You don't want to cause a catastrophic failure of your A/C system components.

 

Need more R134-a. Low freon.

 

I have had the freon checked at the local shop and the charge is good he was to busy to do any other diagnostic so the check was free. i have to try to jumper the low pressure shutoff and does anyone know how to test the high pressure cut out i don't want to jumper it as i don't know if that will send an on or off signal.

 

The system has to function to check pressures so you should be chillin...

 

so I used a jumped on the low pressure cut off and the clutch engages but my e-fan will not come on also the air is a little colder so i am wondering if the freon is really charged and if the mechanic properly checked it. does freon degrade over time but still hold pressure? If i unplug the temp sending unit my fan comes on and it also comes on when i reach a coolant temp of 210 so i know the fan is not faulty. It will be cold here soon so it wont be a long term issue but it would be nice to take my boy wheeling.

 

If I'm not mistaken, the electric fans on the 2000 and 2001 doesn't come on automatically when the AC compressor is engaged. Only comes on when temp reaches 218. At least mine (a 2000) doesn't.

The electric fan shouldn't really have a whole lot to do with the AC cooling I think. I still think your freon is low. I'd buy a bottle and see what happens. You can get one from Walmart with a hose and valve for like $15. Freon doesn't degrade but it can and does leak out over time.

 

Awesome thanks for your help guys i will hit walmart up for a freon charge kit from what i was reading the fan runs when the ac is on but it didn't specify what years that was for thanks again

 

I just had the AC recharged in my 2000 Sport. The shop couldn't charge the system because the bearings in my e-fan were shot and lack of a working E-Fan would prevent the system from working properly and taking on the correct amount of Freon. So the two are definetely tied together cause it works fine now. I would jumper your e-fan back to your battery to make sure it works and test light your fan leads to make sure they are putting out a signal. Than continue troubleshooting if your problem continues after confirming the fan works.

 

I know the e-fan works because when i unplug the temp sending unit the fan comes on at full speed and when the engine temp gets high enough it comes on to help with cooling. Haven't made it to walmart for a recharge kit i think the wife would have been mad at me if i was tinkering with my jeep at our wedding lol.

 

The e-fan working shouldn't make it hard to charge the refrigerant just wont get cooled properly by the fan.

 

Yeah, I would have thought the same thing, but from what the guy said the engine has to be running and when the AC comes on, the fan should as well. Since the fan wasn't drawing air, the freon wasn't cooling, therefore it wasn't dropping in pressure and thereby the system wouldn't fill properly and it would not take a full charge. It seemed a little hooky at the time, but the fan was broken and the system was low, so either way both were getting replaced. He could have told me magical Gnomes and Unicorns were somehow involved and the bill wouldn't have changed.....

 

I know it sounds weird, but in my 92 the AC started working perfectly as soon as I got my E-fan working on a switch. Didn't change a single other thing about it.