Dometric thermostat display blank

Skeeter812 · 06-08-2015, 08:50 AM

Hi. All, hopefully. Someone will have some feedback.
I have a 2013 Montana 3750fl. I brought the rig home yesterday to detail it and when I went to turn on the Ac, I found that the display on the thermostat was blank. I checked all of the fuses in the main panel as well as voltage from the breakers. All was good.
This morning I found that a mouse had chewed the wiring for the thermostat. I disconnected the bad cable and installed a new cable. Still no display.
I talked to the rv dealer and he said that there is a low voltage fuse in the return vent ducting. I removed the ducting cover and could not find a fuse. I did find the cables from the Ac unit but no fuse was to be found.
I then removed the cover on the front Ac unit and did not see a fuse there either.
Does anyone have an idea where the fuse may be located or what is going on?

**hankpage** · 06-09-2015, 05:27 AM

I don't know about the Dometic but the Honeywell in my Cougar has 2 AA batteries for it's display.

**JRTJH** · 06-09-2015, 11:10 AM

I've not seen a fuse in the A/C return air duct (behind the filter) on any of my air conditioners, but there may well be one there that I've never seen. Anyway, the thermostat gets its 12 VDC from a connector in that return air duct. Some of the factory wiring jobs have "cut off the connector" and "hard wired" the thermostat connections. If you remove the entire ceiling shroud you'll find the Romex and also the 3 or 4 low voltage wires. There's a possibility that when you were rewiring, you either pulled one of the "hard wired" connections loose or possibly have it wired backwards ????

Anyway, as for a fuse in the return air duct, if you do find it, please take a picture of it so the rest of us can "learn from your misfortune"....

hankaye · 06-09-2015, 03:30 PM

Skeeter812, Howdy;

Have you checked the rest of the wiring? Mr. or Ms. Mouse probably didn't
just chew on one spot. Took us 6 months to find all(???), of damage that a
toothy rodent did in a airplane fresh out of overhaul. Also, have you
checked inside the cover of the thermostat itself to look for the fuse?

hankaye

You may also like: