1996 Excella a/c thermostat inop?

[Davis]

Hi I have the older 4 button duotherm thermostat on my 96 Excella and has been working fine but now is not switching on and nothing showing on the display. I am wondering if it is not getting power to it. How much voltage should be coming in to the thermostat ? I am only seeing .6 volts. Any help would be appreciated.

[Davis]

Bump

[Davis]

Hello All,
Back when I originally posted this thread in October this problem occurred during my trip from home(GA) to México Beach Fl when I was taking the trailer for family members to use after hurricane Michael. When I got the trailer set up and was going to switch on the a/c there was no display on the thermostat.
I have the trailer back home now and the condition is still the same. So I had asked before if the circuit board in the upper ac unit provided power to the thermostat ? If so how much voltage? Also what else could it be ? Thanks

[A W Warn]

In my 1999 Excella Classic the 12v for the AC unit comes from the breaker panel that is beneath the front window. The breakers have a reset button on the side that will be noticeably extended if tripped. I've had a couple breakers go bad, that I replaced myself. If you have to do this, disconnect shore power and battery cables.

I am pretty sure your trailer is the same. Look at the breaker layout in section G in your Owners Manual.

Inside the AC opening in the ceiling it is a blue wire with a white strip.
(from memory 3 years ago when I replaced the AC)

ps:
these are automotive breakers that can be purchased at most parts stores.
I bought mine at Out of Doors Mart
http://odmrv.com/catalog/index.php?m...roducts_id=706

[Davis]

Thanks for the reply. I checked the 12 volt circuit breakers with a voltmeter and all are good. So I will check the circuit board in the upper unit and see if it has power.

[Davis]

Thanks for the reply. I checked the 12 volt circuit breakers with a volt meter and all are good. I will check the circuit board in the upper unit and see if it has power.

[A W Warn]

I remembered something else you might check.
On the bottom of the thermostat there is a switch that turns the power on/off to the AC thermostat. That switch went bad on mine and I had to find a used thermostat to replace it. That thermostat is no longer available from Dometic. If that happens to be the problem, I MIGHT be able to get a used one from a friend. Send a PM if you need that part.

[streaminwild]

Go outside to the left of the door, there's a access panel with two screws. Loosen the screws and open door and dust cover. In the middle there's a squirrel cage and on the left end is a small black rocker switch. Push that switch up or toward the trailer. Nothing would work on my thermostat until I did this. Let us know what the fix was for future reference. Sorry that I didn't see this thread 4 months ago.

[Davis]

Update:
A few days ago I discovered a 3 amp fuse blown on the circuit board in the upper unit so I replaced that, I also discovered a portion of the wiring that leaves the thermostat had rubbed on the refrigerator coil and burnt so I spliced that still no luck.
So today I retraced my steps I took apart the splice in the wire and re spliced then still had no voltage at the thermostat so I went back to the upper unit and the fuse was blown again so I replaced it went back and switched on the thermostat and it worked[emoji16]. So apparently the bad spot in the wire caused the fuse to blow . All is well now . Thank You for the help.