'97 Dodge Ram P/U 3.7L V6

A/C condensor fan won't run but the A/C clutch functions and the air blows cool when the truck is in motion.

Checked the fuses and relays, all ok.
Metered the connector to the fan , no voltage.

My theory is that it's low on refrigerant and the pressure sensor won't allow the fan to run but why then does the A/C clutch function unless there are more than one pressure switches in the system.

I did notice very short cycling of the A/C clutch, on for 3 seconds off for 3 seconds.

I allways thought that if the refrigerant was too low the system wouldn't work at all.

Any theorys or suggestions.

 

Hmmm, typically if the system is low on refrigerant it will start to act as mentioned and then as it gets lower, halts altogether and will no longer come on. Are you sure this condenser fan works? Try jumpering it to the battery. The pressure sensor theory may not be too far off but on many systems as soon as you turn A/C on the clutch will turn the fan on and runs right off the bat. I would check the wiring, double check the relays and fuses(swap it with another known good) then I would get the system leak tested and topped up and take it from there.

I have had two Dodge's before, closest would be the 95 Intrepid. When I was having leak problems it would do the off/on thing you mentioned but each time the clutch kicked the compressor on the fan came on as well, and shut off when the compressor stopped. I called it my airplane(because thats how it sounded) and I wanted to fly it off a cliff accordingly.