A/C compressor stays on.....Help!

[BFC]

Maybe one of you A/C types can help me here. The compressor on my fiver's A/C won't turn off. If there is power to the RV, it's running. I've replaced the circuit board and thermostat, no go. Any ideas what might cause the compressor to stay on? It's a roof mounted Dometic, just A/C no heat strip.



TIA,



Glenn

 

[RustyJC]

Does yours have a relay (sometimes called a contactor by the A/C trade) in the A/C cabinet to turn on the compressor? Most do. If so, your relay contacts are probably arced shut - the contacts have welded themselves in the "on" position.



Rusty

 

[jdkenyon]

My parent had similar trouble with their ac on the trailer but it turns out nothing was wrong. They would kick on the ac and then fan would shut off after a while when things cooled down but the compressor kept on running. Got to doing some checking and found out it supposed to work that way. Eventually the compressor will shut down, but it depends on how hot it is before that happens. Theirs was a dometic as well.

 

[BFC]

Rusty,



when you say A/C cabinet do you mean from the inside underneath the filter or on the roof under the cover? I replaced pretty much everything up insided the A/C(under the air filter inside the RV, pretty much just left the juice wires alone) and there is a relay on the circuit board, which I replaced also. I haven't gone on the roof yet.



(Edit : You answered it on irv2, thanks!)



jdkenyon,



Well it didn't do it for the first 3 year that I have owned the RV, so I'm pretty sure something up. I'm not the sharpest tool in the shed but... ... ...

 

[RustyJC]

Glenn,



Yep, up on the roof. Pull the cover, find the main power wires going to the compressor motor and start working backward. You should come to a pretty good sized relay. It should be too big to go onto a printed circuit board!



But what do I know - my RV has clunky old stone ax Coleman A/C's.



Rusty

 

[BFC]

went up there, found it, removed it, off to camping world I go!

I'll let ya know if this fixes it, thanks.



Glenn