Dash A/C problems

[roser601]

I have a 2003 Holiday Rambler Endeavor 40 ft. DP that I purchased last winter.
I purchased it with the dash A/C not guaranteed to work and sure enough it doesn’t.
I wasn’t sure who did what, so I borrowed some A/C equipment and recovered the r-134a from the system and evacuated the system for 2 hours with a vacuum pump.
I then dumped 2 cans of 134a into system with system not running. I then jumped out the low pressure switch and started the system and placed the controls on “cool”.
Immediately the low pressure gauge pulled down into a vacuum and the high pressure was reading 140 psi.
I added 2 more cans of 134a but the suction side stayed in a vacuum and the high pressure did not rise much at all.
My thought is a restriction and probably the expansion valve is the culprit-it is probably stuck closed. That is my best guess.
Does anyone else have any other ideas?

[shootist]

It does sound like an obstruction. If not completely blocked the pump should show some pressure on the high side after you fire it up from sitting. If not the pump is bad. The vaccum on the low side is blockage, sometimes one will freeze up when you are filling and pull a vaccum for a few moments. Make sure and replace the dryer with the expansion valve.

[shootist]

One other thing, how big are your cans? It's going to take 60 something ounces to fill and you need to be within 10 or 15 ounces of full before your gauges will make sense.

[Dom]

Check to see if the air is coming cooler out of ducts. Also sounds to me like not enough refrigerant

[RamiDav]

FWIW

The new cans of refrigerant have a safety valve made right into the can .
I found this out the hard way when trying to add some ref

They take an extra adapter or a new type can tap or you will not get the

refrigerant out of the can . The up side is that any extra can be kept because
the valve seals the can . I imagine that is the reason for this new type can

since a lot of ref was expelled into the atmosphere before

Wal-Mart sells a cheap adapter so you can still use your old hoses etc .

[roser601]

Originally Posted by shootist

One other thing, how big are your cans? It's going to take 60 something ounces to fill and you need to be within 10 or 15 ounces of full before your gauges will make sense.

I used 4 full twelve ounce cans and maybe 1/2 of another can and still is down in vacuum on low side gauge with dash fan blowing on high setting.
And thanks, I will search for the drier and try to find it so I can change it also.

[RamiDav]

Originally Posted by roser601

I used 4 full twelve ounce cans and maybe 1/2 of another can and still is down in vacuum on low side gauge with dash fan blowing on high setting.
And thanks, I will search for the drier and try to find it
so I can change it also.

When I had an Endeavor it had an elect
fan for the condenser so if yours has
one make sure it is operating .
The dryer on that coach was up front
but on my 03 Windsor it is located above the differential
so it could be just about any place .



I had a very similar problem with my
air cond so I flushed the system with
a flushing product , replace the expansion valve and drier , that
fixed mine .

Good luck , keep us posted on how it goes

[RobRoy]

It appears that you have a stuck expansion valve and they can be finicky critters.

Here’s a few options I have had positive results with.

1. Try heating the expansion valve with the wife’s hair drier….the thermal shock in some cases will coax the valve free.

2. Pull the system into a vacuum again and recharge the system adding refrigerant very little at a time kind of burping a little in then lock it down and see how it responds

3. Replace the expansion valve and receiver dryer and vacuum and re-charge.

FYI I have seen brand new expansion valves need to be coaxed into working correctly right out of the box ( rare but seen it) and have free them up and used methods 1-2

FYI an in-op condenser fan will drive the high side thru the roof ….. not your problem IMO.

Happy Trails