Skip to main content ↑ ↓
Topic: 2002 U320 Dash Ac wont charge (Read 638 times) previous topic - next topic

2002 U320 Dash Ac wont charge

On my coach I had the Dash AC vacuumed out and when he tried to refill it, it would only take a partial charge on the system. He said it was like something was blocking it from filing it all the way.. is there a valve or something between the rear and the front of the coach? Or the big heater core/exchanger (silver box) under the dash? when he vacuumed everything out he actuall pulled the parts off the rear to see if they were clogged (dryer?) Not sure what the parts are called.

Any ideas.. The vacuum under the steps works and I hear it switching vents and the aquahot works on the 2 vents up top.. There is no heat either to the dash from the dash heat.

Where to start.

Re: 2002 U320 Dash Ac wont charge

Reply #1 –
Find an A/C guy that knows what he is doing.

And, you haven't provided enough information to even toss a dart at what the issue may be.  Why was the system evacuated to begin with?

Re: 2002 U320 Dash Ac wont charge

Reply #2 –
It wouldnt charge so I figured it would be easier to start over with the new freon and oil. Guess not. IS there any expansion valves or anything between the front dash and the rear compressor? something that would stop the freon from filling up to the proper lbs or pressure?

What else would help?

Re: 2002 U320 Dash Ac wont charge

Reply #3 –
If you didn't remove the compressor and dump the oil out of it, and added the correct amount of oil when you recharged it, it will have too much oil. Evacuating the system doesn't remove the oil. There is an expansion valve in the system but don't assume it is the problem. If your air wasn't working to start with did it have Freon? If not you need to find the leak before continuing. If it had Freon and wasn't working it could be the expansion valve. There was a post about someone finding residue from the drier receiver in the expansion valve blocking it. When the person said it wouldn't take all the Freon what were the pressures?
 Basic auto refrigeration knowledge is required to repair these systems. I am not an expert but have been able to have working dash air on all my motorhomes. On another note the heater has nothing to do with the A/C that is another issue. The evap coil needs to have the dash air fan working to check the system also.

Re: 2002 U320 Dash Ac wont charge

Reply #4 –
I will try and find someone that understand the ac and that is all they do but because its a motorhome they are apprehensive to work on it.. thanks

Re: 2002 U320 Dash Ac wont charge

Reply #5 –
Quote from: craneman –
There was a post about someone finding residue from the drier receiver in the expansion valve blocking it.

That was me.  My system was working, but suction pressure was lower than expected.  I changed the TXV and found some desiccant balls on in the TXV inlet.