Resolved Dash A/C not blowing cold air

[Neal]

Brought coach out of storage finally for next trip after 8 months and I don't think the dash A/C is blowing cold air. Recirc etc. Any suggestions in anything I can check? Fuse bay shows all good. 6 years and fine until now. Next Gaffney visit is November.

 

[B52Bombardier1]

Does the AC compressor clutch engage when you turn the system on?

Rick

 

[J&JD]

Were you part of the PDM module Recall? That was one of the known effects of a defective unit.

 

[Webz]

I'm on my 3rd dash AC compressor. As asked earlier, does the clutch engage when turned on?
Do you have gauges to check the freon level? Could be a leak in the system.

 

[Neal]

I had the PDM recall done (twice I think), thanks for the info, I'll put a call in to FL next week.

Where do I find the clutch and what do I do if it's not doing what it's supposed to do?

I do not have the equipment so I'd pretty much have to take it somewhere. I can obviously use the house AC's and I'm scheduled for Gaffney in November so I can get it squared away then. I'm hoping it is just gooked for now somewhere and during some travels ahead it clears itself, or maybe there's a leak. Who knows.

 

[B52Bombardier1]

The AC compressor will have two black hoses sticking out of it and its mounted to the motor with a belt around a pulley on the front. My suspicion is a refrigerant leak and your low pressure cutoff switch is stopping the compressor from engaging - low refrigerant means no oil to the compressor . . . bad.

Don't use sealant in a refrigerant can to fix this!! Sealant contaminates the recovery machines in the professional AC repair shops and those people will DESPISE you. Though, I do recommend the use of UV light dye in the refrigerant to help detect leaks.

Let's hope its not a leaky evaporator or condenser. Maybe just a hose fitting o-ring leak.

Rick

 

[Neal]

Any FL shop can fix this or wait for Gaffney?

 

[Rich W.]

Here’s some interesting reading while you ponder this:

https://newpar.newmarcorp.com/instance1Env99NEWMAR/html/images/SS2013EVEQUILTRAIN.pdf

RV Air Conditioning Service

Servicing your dash air doesn't have to be difficult. In this article we examine how to test, troubleshoot and recharge your RV's air conditioning system.

www.rvtechmag.com

Forum Update – Family RV Association

I’m not very familiar with DP dash AC systems but I should be, and your post got me thinking. I’ll be interested to hear your findings on this one. The many links in the third post in the FMCA link are a good resource.

The problem with leak detection is the 40’ run from your dash to the compressor. Also this means that you system takes a lot more refrigerant than conventional automotive systems. But you can see the compressor from the door side rear compartment so the first thing to check is whether or not it is engaging when running and calling for AC. If you are just seeing the pulley spinning but the center part isn’t engaging, you are probably low on refrigerant. The question then would be why which as I said on these things could be difficulty to identidy.

But the charge ports are easy enough to get to (upper pass side corner under the front hood) so you could just start adding refrigerant (up to 5lbs or more) until the compressor comes on (or doesn’t). As I said I’m no expert here but I’ve done a lot of “standard” auto AC recharges. And in most (if not all) cases, ultimately there was a leak involved.

If you decide to try a recharge to see what happens, this is a good little primer on the subject:

https://www.autozone.com/diy/climate-control/how-to-recharge-car-ac

AC compressor (hard to get to but easy to see)

Refrigerant ports (upper passenger side front)

Cheap one-gauge AC charging gizmo (avail at any auto parts store, usually included with purchase of a two 1lb can kit)

If you add 4lbs or so and the compressor starts kicking in, you know it was low, just not exactly why. But if its a really slow leak, that may get you through the season.

 

[Neal]

Great info, thank you.

 

[osuallen]

We had a thermal switch at the evaporator go out this spring that kept the compressor to engage. it also prevented the engine go into high idle -- weird.

 

[B52Bombardier1]

Any competent shop should be able to do this job unless this is a warranty job. The leak needs to be found and fixed and then the system evacuated down to a hard vacuum. And see if it can hold this vacuum with the vacuum pump turned off for at least thirty minutes. Pulling a hard vacuum removes all air and all moisture from the system - neither of which cools your vehicle.

Consider changing the receiver-drier and /or the accumulator, if equipped.

Cross your fingers that you are running R134A refrigerant and not the new stuff - R1234yf. Given how large of a capacity your AC system seems to be, you will be scanning the horizon for a bank or a liquor store to rob to pay for this repair.

Rick

 

[lostinfla]

While on our trip in '21, we had the compressor go out up in Boardman Oregon (about as far from home as possible). The compressor locked up and shredded the belt. The engine overheated and alarms went off as the engine shut down about 500 ft from the entry to the campground. I had an extra belt but the compressor had melted the clutch assy and wouldn't be usable to run the belt. My wonderful wife, a former parts manager at an auto dealer, got on the phone and found Freightliner Northwest in Hermiston about 15 miles away. They had a new compressor in stock with clutch and the price was only 200.00!! She took off in the toad and picked it up. 105 degrees that day combined with a very hot engine and not really enough correct tools made this a bear to change out, but I finally got it done using the bike rack as a tool bench. Didn't get the air repaired until our trip to Gaffney as the system had to be flushed, evacuated, and recharged with a new dryer, but at least I could fire up the engine with the belt running the other accessories. That fence in the background is the campground entrance. The joys of RVing....

 

[Neal]

Wow! Glad that one worked out for you and you have the know how. The hardest part as we all know in planning for trips is trying to fit in unscheduled service. Now the question is when/where or wait for Gaffney in Nov.

 

[Neal]

Anyone ever used Love's or something similar for service? I wonder if they could handle something like this?

 

[Rich W.]

Anyone ever used Love's or something similar for service? I wonder if they could handle something like this?

If fhey service trucks then they should be able to handle it, but I’d be much more inclined to go to a Freightliner service center. I have a good one an hour or so from here (Sacramento) that I use for any chassis stuff I can’t or don't want to do myself. Their labor rate and parts prices are reasonable and I know they are competent.