Dometic thermostat single zone lcd display

[KAS]

The Dometic thermostat (see attached pic) in my new 2013 Sunseeker 2250LE has stopped working, the LCD display is blank, no matter what I do (RV plugged in, checked circuit breakers, pushed any combination of buttons etc.). I replaced the thermostat, same problem. There is mention of a "control box" on some of the websites that I have researched. On the pictures, it seems to be attached to the actual A/C unit. But since the furnace is also controlled by the thermostat, I would assume that the "control box" controls only the A/C and receives a signal FROM the thermostat, which doesn't work, and therefore wouldn't be the problem. Any ideas?

[Iggy]

Sounds like you lost your 12 volt DC control voltage.
I don't have a Sunseeker but all rigs are similar.
1. Check all of your DC fuses in your panel. Usually located with your circuit breakers.
2. If all is good then I suggest to look at your house batteries and look for your battery control center. It is a closed box similar to the one I show inn the picture. Inside their are 6-8 DC fuses for different things. Like awning, propane detector, steps, etc and check those fuses.

Hope this helps.

[VinceU]

Originally Posted by KAS

The Dometic thermostat (see attached pic) in my new 2013 Sunseeker 2250LE has stopped working, the LCD display is blank, no matter what I do (RV plugged in, checked circuit breakers, pushed any combination of buttons etc.). I replaced the thermostat, same problem. There is mention of a "control box" on some of the websites that I have researched. On the pictures, it seems to be attached to the actual A/C unit. But since the furnace is also controlled by the thermostat, I would assume that the "control box" controls only the A/C and receives a signal FROM the thermostat, which doesn't work, and therefore wouldn't be the problem. Any ideas?

I think you are getting warmer. There is a control 12 volt supply led to the AC. It then downfeeds from there to the thermostat and on to the heater. Reason being the AC fan is called in to circulate the air (without a/c) when the heater is run. Go back to the AC wiring- inside I believe and compare readings with the other unit if you can, if you have two. Somewhere you loosing that signal. See if you can locate a control sketch for the roof a/c. It show the hookup in there.

[KAS]

Originally Posted by VinceU

I think you are getting warmer. There is a control 12 volt supply led to the AC. It then downfeeds from there to the thermostat and on to the heater. Reason being the AC fan is called in to circulate the air (without a/c) when the heater is run. Go back to the AC wiring- inside I believe and compare readings with the other unit if you can, if you have two. Somewhere you loosing that signal. See if you can locate a control sketch for the roof a/c. It show the hookup in there.

That makes sense (after eliminating all the other possibilities). What I don't understand is that it worked last fall and I haven't tried it since. I'll probably have to take it to the dealer. Of course the warranty expired in April! At least I didn't find out during my next camping trip, that would have been a disaster in the heat!

[KAS]

Originally Posted by Iggy

Sounds like you lost your 12 volt DC control voltage.
I don't have a Sunseeker but all rigs are similar.
1. Check all of your DC fuses in your panel. Usually located with your circuit breakers.
2. If all is good then I suggest to look at your house batteries and look for your battery control center. It is a closed box similar to the one I show inn the picture. Inside their are 6-8 DC fuses for different things. Like awning, propane detector, steps, etc and check those fuses.

Hope this helps.

Thank you for the suggestions! I checked all the fuses, they're fine. All other 12V powered items work, so it must be A/C specific. I'll keep looking.

[KAS]

Originally Posted by VinceU

I think you are getting warmer. There is a control 12 volt supply led to the AC. It then downfeeds from there to the thermostat and on to the heater. Reason being the AC fan is called in to circulate the air (without a/c) when the heater is run. Go back to the AC wiring- inside I believe and compare readings with the other unit if you can, if you have two. Somewhere you loosing that signal. See if you can locate a control sketch for the roof a/c. It show the hookup in there.

UPDATE:
I jiggled all the wires in the A/C housing and IT WORKED!!! None of them seemed to be loose, but I'll keep an eye on it.
Thanks for pointing me in the right direction!