Automotive Air Conditioning Information Forum

I recently purchased a 2004 Chevy Silverado 2500HD. I've been having AC issues since I purchased it. Here is the story as short as possible.

When purchased the system had no freon. I had it vaccumed and charged back up at my local shop. It worked, but marginally. It would blow air at temps cycling between 70 and 85 degrees. I brought it back to that shop and they told me it needed a compressor. Replacing that did nothing. They then said it would need a new condenser... That did nothing... Then it needed a new clutch fan in the front. That did nothing... The high side pressure was sky high when they set the low side pressure to spec.

They then called the dealer as they were out of ideas. They recommended they change everything again (above), and clean out the cooling stack. At the end of this, it still was not working properly, so the local shop sent me to the dealer. Dealer first said a sensor would fix the issue (outside temp sensor???). They called me to pick it up as it was "done", and it did nothing to fix the issue. Then they said they'd need to change the clutch fan again in the front. $400ish later, that did nothing (and they called me to tell me it was fixed AGAIN). Then they said that it was the condenser. To be honest, the condenser replacement did do some improvement, but it's still not functioning properly.

The temps are now blowing between 65 and 75 degrees on max AC and I cannot afford to keep taking this thing to the dealer for trial and error that I'm paying for. My wife's vehicle blows 45-50 degrees on the same thermometer I'm using. From what the dealer told me, "everything has been replaced".

I can feel the compressor kicking on and off, and my engine tone changes each time this happens. I'd say I can hear/feel it every 5-10 seconds at idle.

What could we be missing here?

One more thing: The orifice tube was changed 3 times, twice by local shop, and once by the dealer.

Could be a reheat problem from the heater core. If high side was high, misting the condenser with a hose would tell if it were a fan clutch of airflow problem across the condenser. Is this a manual system or automatic temperature control? I would hope they changed the accumulator along with the compressors. Has the system been properly flushed of the oil? By now, there could be too much oil in the system. Also, you mentioned the high side was sky high when they set the low side. You can not set the pressures. You need to weigh the proper amount of refrigerant into the system. This is the only real way to troubleshoot as you're eliminating refrigerant charge as a problem.

The system is an "automatic" system with the digital display.

I do believe the accumulator was replaced, yes. It's shiny and new. Another detail that may help is the lines around the accumulator and accumulator all sweat and continuously drip a tremendous amount of water. When I park, there's a wet spot that is about 2-3 feet in diameter in a matter of minutes.

I don't know about the proper charging of the system, and if there is too much oil in the system.

Lots of condensation means it's getting cold but not inside sounds like your cold air might be getting diverted by baffles, etc.

as dougflas said it might be the temp. control motor inside your interior ac unit your ac might be working very well but the unit stuck mixing hot air with cold air causing high load to the ac unit .