I'm having an issue with the radiator fans on my 02 GC. They turn on once the coolant warms up and work quit well but they will not immediately turn on when the A/C is on. So if I start the van with a cold motor on a hot day and turn the A/C on, the air blows hot/warm until the coolant warms up and the fans start cooling the condenser and radiator. Once the fans finally start to work, the condenser cools right off and the A/C blows ice cubes at my face. But the first 10 minutes of my trip I have to deal with hot temps until the van warms up.

If I do turn the A/C on and leave it on without the fans operating, the high pressure goes waaay up to +300psi.

It seems like something is screwy with the air conditioning circuit because as soon as the A/C (compressor) is turned on, the fans should also turn on. This is how it works with all of my other vehicles.

What can I start diagnosing to find out why they're not turning on? The relay on the front bumper I'm assuming is fine since the fans do eventually turn on. Same with the coloant temp sensor under the ignition coil. I did replace the pressure switch near the A/C receiver/dryer but that didn't change anything. What else could potentially be the issue???

Please help!

 

Have you checked the relay??There is a seperate relay for each fan.The part number for the radiator fan motor relay is
#20369 or 41-5448...
The part number for the condenser fan motor relay is
#MT1443...
If there is another relay in the panel that has an identical part number to the condenser fan relay,borrow it then swap it in place of the suspected faulty relay.If the relay and fan motor are both ok,trace the wiring harness from the fan to see if there are any opens or shorts in the wiring.Disconnect the wiring harness from the fan and test it for power with a test light while the key is on and the ac is turned on max.The wire or fan connecter may also have corrosion on their pins causing a bad connection.