Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

A/C compressor still cycling after charge, Dodge D-1500 pickup

The compressor on my 2001 Dodge pickup was cycling in and out every couple of seconds, and the A/C was putting out hot air. It has not been charged in at least two years. I weighed in exactly one pound and 4 ounces until the compressor ALMOST quit cycling. In fact I had disconnected everything thinking I was done. I don’t see any evidence of leaking anywhere. The system holds two pounds. Since there was some refrigerant still in the system I did not purge it. I do not have a vacuum system or a holding tank anyway, just a nice accurate digital scale. Now it cycles maybe once every three or four minutes. I have 120 over 35 pounds on an 82 degree day, and 43 degrees at the vents. My questions are should a Dodge compressor cycle at all, and should I add more R134a?

The high side should be closer to 200psi…Try another 1/2 pound…

That would mean that the two pound system was almost completely empty, which it wasn’t. Or was it? Will the compressor continue to “try” even when it’s that low?

Was the AC switch on MAX and the fan on HIGH? It should be.

Yes to both questions

It may still be slightly low. It is normal for the compressor to cycle. This is how the system keeps the evaporator from icing up.

I put in another 4 ounces. That’s darned near a full two pound charge. It still cycles, but it’s cold. I guess I’ll call it good. Thanks for all of your input.