Dash A/C Died Today

[CaptainKip]

Anyone know of some things I can check out?

We're on the road in the midwest.

Thanks!!

[jacwjames]

You might try buying a can of 134a and trying to recharge it. You can buy these at Walmart or any auto store. It might get you home.


When I bought our rig in 2008 the AC blew cold. After about 4 years it didn't work, added a can and it took right off.



I also have a separate belt that drives the AC compressor.

[Randy125]

When you say died do you mean the blower quit or the air coming out is not cold anymore?

[CaptainKip]

Hey Randy... good question... the air is not cold.

Pushing the AC button on the rotary dial doesn't result in anything.

Before where the AC was running, we'd have this noise we described as similar to a siren that would come on regularly and cycle on and off. It would stay on longer, the colder the temp dial was set. The siren noise is gone now.

Thanks for asking.

[DRM901]

That sounds like the compressor isn't turning on. Look at the clutch on it to see if the inside of that pulley is moving. (The outside is always moving.)

If it isn't moving, there are a lot of things that could cause it to stop. Low on freon, bad clutch &/or compressor, fuse, etc.

[Randy125]

Originally Posted by DRM901

That sounds like the compressor isn't turning on. Look at the clutch on it to see if the inside of that pulley is moving. (The outside is always moving.)

If it isn't moving, there are a lot of things that could cause it to stop. Low on freon, bad clutch &/or compressor, fuse, etc.

Yep I agree.

[TNCRAIG]

My A/C stopped woking last year when I was having issues with the PDM that is currently under recall. The Freightliner tech said the PDM did not control any part of the A/C but after it was replaced last September it has worked without issue. Apparently one of the relays that operate the clutch was impacted. I generally run my generator and the roof A/C units as it does not impact the fuel economy as much and it exercises the generator as well as cools the whole coach.

[Skip426]

Kip; it looks like you're posting from two devices , be aware that posting using iRV2 app doesn't add your signature line to your post .

EDIT: Is your engine the 6.7L Cummins ISB ?

[CaptainKip]

OK... this is wierd... after not using the AC all day yesterday and today, as we were pulling into our destination for the night, it was getting a little hot, so on a whim, I pushed the AC button and we got cold air! It ran the last 10 minutes of the trip.

Thoughts?

[CaptainKip]

Hey Skip... oh snap... I didn't realize. 2018 37PA. Yes, 6.7L ISB.

[CaptainKip]

We ran the AC all day today... it acted perfectly normal.

[Skip426]

Originally Posted by CaptainKip

We ran the AC all day today... it acted perfectly normal.

Intermittent issues cost me most of my hair during 33 years at a Chrysler dealership .

[DRM901]

I would check the wires to the clutch, fuses, connections behind the dash. Sounds like a bad connection, periodically. Just clean any connection (with electrical cleaner spray) in the engine compartment and reattach. Tighten all connections behind the dash.

[MrMark52]

Originally Posted by jacwjames

You might try buying a can of 134a and trying to recharge it. You can buy these at Walmart or any auto store. It might get you home.


When I bought our rig in 2008 the AC blew cold. After about 4 years it didn't work, added a can and it took right off.



I also have a separate belt that drives the AC compressor.

Please don’t! This is not the right way to make an air conditioning system work.

Too much charge, you’ll ruin a compressor, or worse.

Too little charge, you’ll ruin a compressor.

The only way to properly repair a system is to 1st - determine if there was an extenuating set of circumstances that would cause the A/C to quit blowing cold air, then
2 - following the chassis and A/C box unit manufacturers recommendation, measure the discharge air temperature, relative humidity, and engine rpm to ascertain said discharge air temperature is within spec, then
3 - if temps are out of spec, do an inch by inch inspection of all refrigerant lines, hoses, connections for signs of oil (oil always escapes where refrigerant leaks) and note for subsequent repair once the system charge has been removed, then
4 - quickly make repairs after the refrigerant has been removed, then
5 - pressure test the system with dry nitrogen to insure all leak points have been fixed, then
6 - replace the filter drier, then
7 - test once again for leaks with dry nitrogen, then
8 - evacuate to 500 microns, then
9 - weigh the appropriate system charge into the system. System charge information should be labeled somewhere on the air box, usually in the engine compartment (this is a DOE/EPA requirement).