Dometic A/C problem

Dsm1957 · 08-23-2021, 07:51 AM

I have a 2020 34RSBS with a Domestic AC and digital thermostat which is also a Domestic. My problem… one day AC is working great, the next nothing. The fan won’t even come on. I can get the furnace to come on using the thermostat but that’s it. All other 12v systems are working fine. Checked the breaker, looked for lose connections, everything looks fine. Tried reset on the thermostat, nothing. Any other ideas? Don’t want to do to much as it’s still under warranty, but if there’s a simple fix I’m all ears!! Thanks in advance.

mini4mw · 08-23-2021, 08:20 AM

not sure if the fan is 12v or 120, but the AC will be 120v. Does the microwave work? IE, are you sure you have 120v coming into the trailer via shore power or generator?

Dsm1957 · 08-23-2021, 08:34 AM

Yes, everything else in the trailer works just fine.

Dsm1957 · 08-23-2021, 08:59 AM

Quote:

Originally Posted by mini4mw

not sure if the fan is 12v or 120, but the AC will be 120v. Does the microwave work? IE, are you sure you have 120v coming into the trailer via shore power or generator?

Yes, everything else works fine.

mini4mw · 08-23-2021, 12:04 PM

If you've checked the breakers (maybe reset even if they look ok) and 120v working everywhere else I'd think it would be in one of these spots:

1) get a multi-meter and set to AC 200v, check the breaker to ensure power is being passed. Should see ~115v between hot and neutral. I've seen a few posts where the breaker wires come loose or were never tighten down right causing something to stop working. Be careful getting in there.. that's 120v and you don't want to cause a short and melt anything (make it worse) or shock yourself. If you don't have a multi-meter you can still check to see if the wires are secured/tight.

2) take off the thermostat and make sure all the wires are tight. Seems like this is probably fine since the heat works, but perhaps its just 1 wire that goes to the AC.

3) take off the inside shroud to the AC. Where the air goes up to be cooled there is a control box, make sure the wires are tight there

Attached is a picture of the control box up in the AC intake.

Parcany · 08-23-2021, 08:49 PM

Pull the cover off of the thermostat very carefully and try and push the knobs lightly to get the ac to work. If the ac works very gently put the cover back on.. The thermostat is a piece of crap in my opinion. If you push to hard it won't work either. Have to have a very lite finger.

You may also like: