Dash A/C

[Kaputnick]

Dash ac blowing hot air, hooked up recharge kit with engine running and it was showing low. Dining the testing the ac was on full cold setting at maximum. I never heard the ac clutch kick on until I started adding the refrigerant.
After a few seconds I checked the PSI and it was in the 40 range (80F) outside. Then the clutch would kick off and go back to 0; kick back on and back to 40? This continued with no decrease in temperature at the dash registers.
I am afraid to go any higher with the pressure, an thoughts? The ac unit was replaced in November 2020.
Thanx!

 

[Ray-IN]

Lets jump back, why was it replaced, which components? This complete heavy-duty air conditioning service manual explains everything: https://www.btrac.com/documents/svc-manual-revision-i-feb-2011.pdf
RV refrigerant charge information: https://www.proairllc.com/pub/media/pdfs/eti-Refrigerant Charge Information - R134A Systems.pdf

 

[scottydl]

If the AC was replaced in 6 months ago, and (I assume) the rig went into storage... and now is blowing hot air coming out of storage, I think I'd be heading back to the shop that did the replacement. There's no reason refrigerant should be leaking and need replacement at this point.

 

[John Canfield]

I've done extensive troubleshooting on my dash air to the extent of replacing everything behind the 'hood.'

There are two common problems:

- vacuum pump to operate the blend doors fails
- the dryer/filter gets clogged up (if one fitting is cold, it's clogged up)

A less common problem:

- I found a leaking crimped hose fitting on the expansion valve, replaced the hose

Since I'm a tool collector, I now have a complete collection of HVAC service tools, I figure I broke even on the repair - a shop repair would be $$$$, I spent $$$$ on service tools.