Help with Dometic Digital Thermostat

[D_E_Bishop]

We're somewhat isolated here at the beach with very slow internet and our Cousin is having trouble with her furnace. She has a two year old rig and the heater won't come on. I found that the Dometic TS #3313189.023 is a three wire and I know from nothing about them. I know where the control panel is and thought I could check the output to the furnace for twelve volts but after that I'm lost if there is no 12 volt out put. She really doesn't want to drive home and have it fixed so I thought I'd check if it's the furnace or the thermostat/control panel.

Is there some way to check if the Furnace feature of the TS is working? All the other functions work. I thought I'd reinitialize the control panel today but other than that is there anything I can check in the TS system. I've verified that there is power to the furnace. I just have my little Fluke DMM so it's just a basic DMM.

If the furnace is getting 12 volts, I can troubleshoot that but not the electronics of the TS.

[dougrainer]

Chris Bryant wrote:
The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.

Here's how to put it in diagnostic mode:
http://bryantrv.com/docs2/docs/singlezonediag.pdf

Go to the ROOF AC control board. There are those 2 blue wires. When set to turn the furnace ON, BOTH those wires should have 12 volts. When the furnace is OFF, only 1 of those wires will have 12 volts. IF NONE have 12 volts, your furnace fuse is either blown or you have a wiring problem AT the furnace. Doug

[MrWizard]

Is that the little 3" square 'single zone'
Controls one heater one A/C unit

My uncle has that in his new class B, (traded off his Thor Serrano)
Seems to be a troublesome design, and it has a slow response

Try changing mode to heat , run the temp up to something like 80 or 90(for testing)
Then set to ON do not set to auto
Then wait , could take two minutes or more to come on

There was another thread few days ago, somebody wanted to replace it
Options are limited , it's a proprietary digital system
I saw a schematic posted someplace of the control box wiring
Maybe it was from Chris

[Chris_Bryant]

The furnace hookup is a simple relay- two blue wires at the control box. One wire needs a 12 volt feed, turning the furnace on simply closes that relay.

Here's how to put it in diagnostic mode:
http://bryantrv.com/docs2/docs/singlezonediag.pdf