Q: Cooling fan kicks off when the AC is on, on a 2000 Cherokee XJ

No, it is not normal. They shouldn’t cycle that fast. When the fan is on, the fans generally run as long as the compressor is running. So, if you live in an area where it’s really hot like Arizona, you might find that those fans are running the whole time but they shouldn’t kick on and off.

Yours is kicking on and off a lot. What you’d want to do is watch your AC compressor and if you see the fans kicking on and off and if you see the compressor kicking on and off, you’ve got an air conditioning problem. That’s often because it is either low on refrigerant or there is a restriction in the system, and then when there is a restriction in the system, the pressure builds up and the pressure switch turns the compressor off and the compressor and the fan go off. Then, as the pressure goes down, it turns it back on and then the fans come on. But, then the pressure builds up and it turns it off. So, you’d want to check that. You probably have a problem in the AC system. If you want to have this verified by a certified technician, a mechanic such as one from YourMechanic, can come to your home or office to inspect your AC system.