George00XJ

Hey Guys, I have a 2000 Jeep XJ. *FIRST ISSUE* When my AC works, it blows 48/49 degrees out the center vent, the tank and hoses under the hood are cold with condensation. When it don't work, it blows in the 70's out the center vent and the components under the hood are warm. The AC will blow cold for about 20-30 min, then stop blowing cold. Also if blowing cold, turn the jeep off for 10 min, back on, the ac will not blow cold unless I let it sit about 2 hrs. There are no leaks in the system.
*SECOND ISSUE* The AC blows cooler when the electric fan kicks on, and about 5 degrees warmer when the electric fan kicks off. I want to have the electric fan on continuously when the motor is running. I don't want a manual switch in the cab, I want it to work automatically when I start the jeep. Thanks

PatHenry

What is the reason for wanting it to run continuously, just because the AC is colder? If so you're looking at it backwards - the AC causes the fan to turn on, so when the AC stops running the fan shuts off. Just getting the fan to run will not make the A/C run better.

I would correct the A/C issue and leave the e-fan as it is.

investinwaffles

On the 97-99 XJ, the E-fan kicks on with the AC compressor regardless of hot-side pressures

On the 00-01, the E-fan only triggers when pressure is high enough, indicating that the condenser is hot and needs additional airflow.

This would indicate that you don't have adequate refrigerant pressure, which would cause the E-fan to not kick on early enough because it thinks the system is cool enough already (pressure not high enough to trigger the fan). I would have an HVAC shop check refrigerant levels to start
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Adding an e-fan switch is a nice feature, helps regulate temps better

4.3L XJ

I concur. You have a slightly undercharged AC system and when that happens in a fixed orifice system it actually runs too cold and the evap coil turns into a block of ice. Hence, in two hours the ice is gone and it works right again. A little R234A will take care of that. However, it also means you have a slow leak.