Hi Folks,

I'm having an odd problem with my A/C. My A/C will blow cold for several minutes, and then blow ambient air temp. If I turn the A/C off for a while (ten minutes), and then turn it back on, it's cold again. Then, the cycle repeats. It has a fresh charge of R134A. I had this same problem when I was using R12.

Engine temp is always below the 1/2 mark. Radiator is new, and the condenser is clean. This problem occurs at both, high and low speed. The truck has 98,000 miles on it. 22R engine with 5-speed.

Any ideas would be greatly appreciated.

Thanks

RoyBoy

 

When you charged the ac, did u empty it and then refill? Or just top off?

 

Vacuumed for 30 minutes and filled using shop A/C machine.

 

Does the compresssor stay running? Maybe the temp sensor for the ac?

 

I tried the A/C again today. Good for 15 minutes and started blowing warm. I stopped the truck, and the compressor was not engaged. So, what can be failing that causes the compressor to turn on and off randomly?

Pressure switch. Bad fan clutch. Other.

Didn't know I had an A/C temp sensor.

 

If u have a manual look at diagram for the wiring. I will check my manual tomorrow afterwork. If anything check all,the connections/wiring that u can see. When the ac went off was the button on the dash still on? I dnt remeber if there is an ac temp sensor or a pressure switch. Pressure switch is on newer systems and its designed to turn off the compressor if there is a drop in pressure so the compressor wont burn up. Hope this helps until i can look at manual.