Finally! The shop that was doing my A/C conversion was able to diagnose the problem of the radiator fan staying on all the time.

The fan would not be running until the system was charged with freon. Then, it would run continuously, even with the A/C off. The issue was the compressor switch on the backside of the compressor. He had tried 3 other switches (different brands) with the same results of the fan continuing to run. Finally, he used the FourSeasons switch, and the fan only runs when the A/C is on Max, or the temperature sensor reaches a high enough temp to trigger the fan.

I hope this helps anyone else who has had troubles during A/C conversions. Thanks to all on Pennock's whose input helped us down the road to solving this issue. My Fiero is BACK!

Attached is a photo of the parts box for the compressor switch that worked properly.

Wrong fan switch, makes sense. Any idea what incorrect one was in there previously? The one for the V5 compressor?

The only one I can remember is a switch from NAPA. I don't know the manufacturer of the switch.

The others were Santech and AC Delco. You would think that the GM part would work correctly. Guess not.

[This message has been edited by sledcaddie (edited 08-11-2021).]

You state

quote fan only runs when the A/C is on Max

. I believe it should come on in Normal and Bi-Level, or there is something wrong with my car.

Jack

The fan will come on continuously when MAX is selected. When Bi-LEVEL or NORMAL are selected, the fan will come on when the engine temperature reaches a set temperature, usually 190-200 degrees or above.

What year is the car?

Jack

This recent one that was converted is an 88 GT.

Did you install a Variable Orifice Valve?