2nd Gen Non-Engine/Transmission A/C not cooling...

[stvntylr]

My A/C in my 98. 5 Ram 5. 9L 24V CTD stopped cooling and is fully charged with no leaks. The compressor is cycling on and off rapidly.



Any ideas what might be going on with this?

 

[B.G. Smith]

What are the pressures on suction and discharge when the engine is running with ac on? bg

 

[stvntylr]

Not sure, and I don't have the equipment to check it. Only way I knew it was still fully charged was I took it in Friday at 4:30 to the place I had charge it (had it charged about 2 months ago). They said that they would check for leaks and recharge it to get me through the weekend, but after they checked it, they said it was fully charged still, compressor was working but cycling rapidly and to bring it back in on Monday so they could take more time to look at the problem.

 

[B.G. Smith]

The ac compressor is cycled by a switch mounted in the accumulator or suction side of the compressor. Should cycle off at about 26# and back on at a little over 40#. Bet you are gonna find that is is low on refrigerant. bg

 

[stvntylr]

Thanks, I'll report back when fixed...

 

[ESwartzer]

Ac

May be a blocked orifice in the HP line.

 

[stvntylr]

OK, at least I have an alternate problem I can have them check. I stopped by the shop yesterday to make an appointment so they could finish diagnosing (and hopefully fix it), and they did say that it is definitely full, the compressor is good, the clutch is good. It just appears to not be circulating the freon, so that would fit the symptoms I think...
Thanks for the input, everyone. Much appreciated.

 

[Cosmo]

I just fixed an 05 Tahoe that had multiple issues affecting the A/C system. Once I replaced the PCM and rewired the harness connector, the clutch was engaging but it wasn't circulating the refrigerant. The clutch was working, but it had delaminated from the hub of the compressor, so the compressor shaft wasn't spinning.



We've also seen a few compressors with broken shafts, so it looks like it's working but it's not.