Aria dash air not working

[m1noel]

Our dash AC is inop. The compressor does not start, no power to low pressure switch. Gauges show good pressure, so I believe it has to be electrical. Cannot find fuse or relay or dash wiring diagram to I can trace power at/from switch. Any Ideas?
Mike

 

[javelin-THOR]

So I am not an AC expert by any stretch and I don’t know your Diesel coach systems either, but sometimes dated information for various RV systems stays “relatively similar” over the years.....or at least can provide some basic clues to what your dash AC controls “might also” do.
The compressor clutch control pressure switch monitors both for high and low pressure conditions I believe.....so if you are in the normal range for your system pressure that is good. You say there is no voltage on the wire from the dash controls calling for the AC clutch to operate.......so I wonder if there is some other safety device like an ambient air temp sensor in series with the pressure sensor to prevent the clutch from operating with too low a temp outside. Since it is certainly warm enough outside now, perhaps the temp sensor (if equipped) has failed open? The other source of the clutch control voltage should be the dash AC/temp controls I would think; and of course fusing of some kind. I don’t know the fusing for your coach so I don’t know if there is one fuse for the clutch or not. If the blower motor works then maybe checking for voltage on the AC; MAX AC control switch on the dash would be a next step?
I am attaching a link to an “old” 2005 Winnabago RV dash AC/Heater control document that could be totally useless......however it may give a few clues to help move the yard sticks down the field for your trouble. If my link works, scroll down a bit to the rotary dash control schematic (this shows both electric and vacuum controls). I noted on the older push button dash controls section, that they show a temp sensor in series with the pressure switch. I hope there is some helpful info that can be applied to resolving your problem. When we don’t have current schematics for our coaches we have to be detectives sometimes.


https://winnebagoind.com/resources/service/pdfs/2005-06 Auto Heating & AC.pdf


Good luck.

 

[m1noel]

Javelin,
Thanks. Those drawings for the rotary control and wiring are exactly what I need, just for our Thor. The control box is sealed, and I can't tell what wires are for what. Hoping to get diagrams from Thor after the holiday.
Mike

 

[LDK]

Our dash AC is inop. The compressor does not start, no power to low pressure switch. Gauges show good pressure, so I believe it has to be electrical. Cannot find fuse or relay or dash wiring diagram to I can trace power at/from switch. Any Ideas?
Mike

Hi Mike. My front dash AC is not working either. Any findings that may be helpful?

 

[m1noel]

Hi Mike. My front dash AC is not working either. Any findings that may be helpful?

Not yet. Taking it to freightliner for a recall in the next week or two. Going to see what they find.

 

[LDK]

Not yet. Taking it to freightliner for a recall in the next week or two. Going to see what they find.

Thanks Mike. Taking it in related to the recall discussed in this post?
https://www.irv2.com/forums/showthread.php?t=413740

My chassis is included in the recall and need to get it to Freightliner.

I see dash AC mentioned in the post.

I also have right tear tailights out (signal, brake, etc). Not sure yet if related to the recall.

 

[m1noel]

Yes, that is the recall. I had not seen the post about the A.C. Thanks for posting that for me.
Mike

 

[m1noel]

Got it in to Freightliner , yes the recalled PDM was bad, but was not the problem with the AC. AC compressor clutch was bad, they ordered that, and when they went to install the new clutch, damaged the compressor. Compressor is on national back order, so don't know when we will get one. Good news is all covered under Freightliner warranty, and running the roof air with generator and using the dash vents on recirculate cools very well.
Mike

 

[Carole H.]

I just took my 2019 Thor Aria to Freightliner for the turn signal brake light recall. Our dash air has quit working also. On our way back from camping last week, we heard a loud pop, that actually sounded like a tire blowing out and the dash air is now blowing hot air. When we arrived at the Freightliner dealership, a mechanic came out and said "Oh, that dash air not working could be tied into the PDM that is under recall." My husband said, "Yeah, I guess that loud noise we heard was the PDM exploding and I guess it smells like freon also." I hope that is not the idiot that is going to be working on our coach. He also hinted at blaming it on a possible Thor problem. We told him it was our dash air and not the ac units on top of the motorhome.

 

[Jpchoc3]

Vicki & Mike... We have a 2017 Thor Aria 3901 and our dash AC unit is not working AGAIN! Wow... this forst time was about two years ago when the fan motor was working really well but the compressor was inoperable. We had it repaired and it was determined that there was some obscure wirin problem. Ok???

Today I go out to my unit to fill it was diesel fuel and discovered that my dash AC unit is not blowing any cold air AGAIN! Same issue as before. We live in area where temperatures soar above the 100 degree mark. We leave in the morning and will not have dash AC again. We will be forced to use the overhead unit during the drive. Unbelievable... When I have it serveiced and/or repaired I will repost the solution.

 

[simidrm]

The ac system uses a virtual fuse, part of the engine ecm if a fault is found in the system the virtual fuse will open and prevent the system from working to keep the compressor from exploding from lack of freon or other issue's what type of diagnostic connector does your chassis have?

You can try unhooking the batteries for a few minutes it will sometimes clear a fault,
i dont know what chassis your rig sits on but some systems use a thermistor for high and low pressure and they are known to go bad usually found on international chassis ,
Not sure what ford uses but freightliner chassis have a high and low pressure switch and a thermostatic switch in the air duct to control evap temps, are you getting power to the compressor clutch? use a ohms meter and unplug compressor and check for a open circuit on the clutch

 

[simidrm]

I just took my 2019 Thor Aria to Freightliner for the turn signal brake light recall. Our dash air has quit working also. On our way back from camping last week, we heard a loud pop, that actually sounded like a tire blowing out and the dash air is now blowing hot air. When we arrived at the Freightliner dealership, a mechanic came out and said "Oh, that dash air not working could be tied into the PDM that is under recall." My husband said, "Yeah, I guess that loud noise we heard was the PDM exploding and I guess it smells like freon also." I hope that is not the idiot that is going to be working on our coach. He also hinted at blaming it on a possible Thor problem. We told him it was our dash air and not the ac units on top of the motorhome.

Frieghtliner did have a recall on the brake light switch on vehicles using air brakes, the problem was air pressure would bled through the switch and push the wires out of the plug making brake lights inoperable,there cure was to remove the silicon plug on the back of the plug to allow the air pressure to escape without pushing the wires out, they also have a recall on the pdm (power distribution box) the lids were not keeping water out and corroding the backs of the pdm and the recall consist of inspecting the pdm for water intrusion and either replace the lid with an upgraded one or if water corrosion is present to replace and reprogram the pdm, but that pdm has no control over the a/c system that is controlled by the sam cabin module and with the pop you heard I would suspect you either blew a high pressure hose or the condensor let go, Frieghtliner uses a dye from the factory when they charge the system so look at all the a/c system lines and compnets for a oily area and if you have a uv light look for a greenish dye.

 

[simidrm]

Funny thing the sanden a/c compressor clutchs are not replacable so no surprise the damaged it.

 

[Rikadoo]

Dash AC compressor won't engage

I know this is a old thread however I have a 2019 Aria that has just recently got no cold air out the ducts. I have checked the state of charge as well as determined the clutch is receiving NO POWER to engage. when I hook power directly to the clutch it works just fine, I have tried to locate fuses however I am coming up short as the fuses I did find in the wheel well at the left front are not identified yet there are some empty slots that fuses could go into. Of course reading the owners manual does not list any fuses or where to find them, is does offer plenty of Safety advice when replacing one...Please! Any advise would be greatly appreciated:bow:

 

[LDK]

I know this is a old thread however I have a 2019 Aria that has just recently got no cold air out the ducts. I have checked the state of charge as well as determined the clutch is receiving NO POWER to engage. when I hook power directly to the clutch it works just fine, I have tried to locate fuses however I am coming up short as the fuses I did find in the wheel well at the left front are not identified yet there are some empty slots that fuses could go into. Of course reading the owners manual does not list any fuses or where to find them, is does offer plenty of Safety advice when replacing one...Please! Any advise would be greatly appreciated[emoji144]

Have you had the PDM changed out as per the Freightliner recall mentioned in this thread?

 

[LDK]

Have you had the PDM changed out as per the Freightliner recall mentioned in this thread?

I just remembered there have been multiple recalls related to the PDM. The latest being "A secondary fused harness will be added which bypasses the affected suspect portion of the PDM."