cressida fan not kicking on.

Check the engine cooling fan clutch to make sure it locks up when the engine is hot.

The AC condenser fan is probably controlled by something in the AC system, not the engine cooling system.

the engine cooling system.

Ya the a/c high pressure switch controls the electric fan. Poor condenser air flow would make it cycle on like that from high high side pressure if the engine fan clutch was bad.

Crap blocking the airflow between the condenser and the radiator. Or the condenser front side could cause the a/c fan to act like that also.

GL Dan

Thanks folks for your input. I ran some extensives tests on the vehicle and noticed that after 30 minutes of continuous operation with AC on, the high pressure drops below 200 and the fan will not kick on. Meanwhile, the car starts to overheat. If I turn the AC off and then turn it on after about 3 minutes, the high pressure back to 250 and the fan kicks on. Also noticed that the EPR and pipe leading to the compressor was all frosted up.

Whats happening here?

thanks again!

Check the sight glass in the receiver drier when the AC compressor is engaged. It should look like clear water flowing past the glass. If you see foam, there is air in the system and it needs to be evacuated and recharged. The pressure drop can mean that there is moisture in the system and the expansion valve is freezing.

You can check the operation of the pressure switch, I believe it is near or on the receiver/drier.