Community Forums

js9315 · 07-29-2008, 06:19 PM

I have a 2003 Pace Arrow on the W22 chassis. The dash AC has never been great but lately it has gotten very bad.

First indications were that the compressor and fans would not run (I do not have a Max AC position on my controls, just turn it all the way cold, AC button on, and in Recirculate) so I checked the freon and it was low, added 12 oz (1 small can) and it was in the normal operating pressure range and the dash was making cool air (back to 'normal').

Now a month later the system is only putting out hot air (~130 degrees measured with a IR temperature gun). The coach has been in storage since I added the freon. Thinking I had the Tempcon valve problem I took a set of vise grips and closed the heater hose to the heater core and waited. I also connected the gage again and the pressure is still the same as after I added the freon a month ago.

On thing I did notice is that both electric fans were running (good) but the compressor would cycle 3 seconds on, 10 secoinds off (not good). Watching the gage, when the compressor cycles on, the gage drops to zero and then the compressor turns off and the pressure comes back to normal, 10 seconds later it tries again, same cycle, compressor on, pressure drops to zero, compressor off, pressure returns to normal. I let the system run about an hour with the heater hose closed off and the discharge temperature did not change, hanging in there at about 130 degF.

I will probably take the coach to Archer or PPL to have them look at it, I have a warranty on the coach that will most likely pay for the repairs but am looking for some insight on what might be wrong. Any ideas???

TIA

js9315 · 07-29-2008, 06:19 PM

I have a 2003 Pace Arrow on the W22 chassis. The dash AC has never been great but lately it has gotten very bad.

First indications were that the compressor and fans would not run (I do not have a Max AC position on my controls, just turn it all the way cold, AC button on, and in Recirculate) so I checked the freon and it was low, added 12 oz (1 small can) and it was in the normal operating pressure range and the dash was making cool air (back to 'normal').

Now a month later the system is only putting out hot air (~130 degrees measured with a IR temperature gun). The coach has been in storage since I added the freon. Thinking I had the Tempcon valve problem I took a set of vise grips and closed the heater hose to the heater core and waited. I also connected the gage again and the pressure is still the same as after I added the freon a month ago.

On thing I did notice is that both electric fans were running (good) but the compressor would cycle 3 seconds on, 10 secoinds off (not good). Watching the gage, when the compressor cycles on, the gage drops to zero and then the compressor turns off and the pressure comes back to normal, 10 seconds later it tries again, same cycle, compressor on, pressure drops to zero, compressor off, pressure returns to normal. I let the system run about an hour with the heater hose closed off and the discharge temperature did not change, hanging in there at about 130 degF.

I will probably take the coach to Archer or PPL to have them look at it, I have a warranty on the coach that will most likely pay for the repairs but am looking for some insight on what might be wrong. Any ideas???

TIA

Bagman57 · 07-30-2008, 01:50 AM

We have an 04 W-22 Allegro Bay and this spring I noticed that our dash air wasn't blowing cool air. Well it just so happens that there is a HD Truck Air-condit. & Radiator repair shop just eight business down the street from us and we took it there and the problem was old worn out seals that let all the refrigerant leak out. They put in two new seals and recharged the air and now our dash air is is absolutely great! Spent less than $200.00. Bagman57.

TandW · 07-30-2008, 02:25 AM

Please check the charge again. Seems that low-side switch. is saving the compressor. Check for minute oil accumulation at AC fittings, hose rubs, compressor shaft and compressor manifold. Good luck !!

js9315 · 07-30-2008, 11:57 AM

Thanks TandW, you hit it right on the head.

I added freon and when the pressure came up the compressor kept running, I was able to add about 18 oz of R134, also put in a leak detector and found a loose connection on the receiver/drier. We're putting out cool air (77 deg F) which is almost 30 degrees less than ambient so I think it is working fine. I added until the low side pressure was a touch over 40 psi and will check it in a couple of days to see if it is still leaking or if I got all of the loose connections.

Thanks again.

dieselclacker · 07-30-2008, 01:49 PM

js9315, If your utput temp is only 77 degrees, you have a problem, as this will not cool down your coach. It may be still low, as the pressure you reported, 40 psi, is a little on the high side. Do you have a sight glass near the reciever drier so that you can check for bubbles in the 134? May still be a little low.

Dieselclacker

js9315 · 07-30-2008, 03:39 PM

Dieselclacker -

The receiver does not have a window and I can't get to the inlet tubing on the compressor to see if it is sweating. The Workhorse repair manual states the lo side pressure should be 40 psi with the AC on high. I was tempted to add more R134 but did not want to risk getting liquid into the compressor or increasing the lo side pressure any higher.

I would like to have a lower output temperature but I seem to remember from my old A school days that what you are looking for is a delta between the ambient temperature and the discharge temperature of about 30 degrees. The ambient temp was in the 110 degree neighborhood so a 77 degree output is right in that neighborhood.

The only other thing I can think of is that the system has a lot of air in it and needs to be evacuated (do they still do that on R134 systems??) If that is the case I will have to get some professional help...

TandW · 07-30-2008, 04:10 PM

A lot of coaches suffer from inadequate isolation of the engine compartment from the inlet side of the radiator and the bulkhead around it. Hot engine air can easily recirculate forward when the bulkhead has been compromised, swamping the radiator with hot inlet air, and potentially introducing hot air to the hvac inlet and the engine air intake. This condition is most noticeable when standing still at a hot idle. Good luck sealing up that bulkhead!!

js9315 · 07-31-2008, 07:37 AM

TandW -

One thing I have on my list for 'later' is to figure out all of the duct routing for the dash air. I do not have a recirc intake at the floor on the passenger side, do not have a Max AC position on the control, etc. I have purchased insulation for under the carpet in the cab to help keep the engine heat out of the cab and am looking for something to apply on the other side; recently ran across an insulating paint that can be sprayed on that might work, need to do more homework though). I will be doing a rather major remodel sometime soon and plan on fixing the insulation and duct routing issues along with the remodel.

Thanks for all of your help, I'll let you know how it comes out.

tropical36 · 08-30-2008, 12:16 PM

Our rigs do sit a lot...not good for the AC. I would suggest that if you add a can, you get one with oil and leak sealer, so just maybe as you run it for an extended period, things will seal themselves.
I recently got myself a set of gauges and a large tank, which should save us in the long run....as the whole family of 3 generations have vehicles using R134A now.