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Traveling RN · 07-06-2014, 01:57 AM

I have a Dometic Duo Therm 5 button thermostat that controls 2 roof mounted a/c units. I came home after a big storm and found my generator running and no display on my thermostat. It worked prior to this. I replaced the thermostat and control box and checked all the fuses in the control box and fuse panel and all are OK. Still no power to thermostat after replacing all of these things. Now where do I look? Thanks for the help.

Jeff

"007" · 07-06-2014, 02:42 AM

Welcome to irv2.
The first control unit in your front AC. ---Trouble shooting Guide
Or possibly resetting the thermostat, also reseat the cord into the thermostat.

RV Wizard · 07-06-2014, 03:45 AM

Hello and

. We are glad to have you join us here and we look forward to reading of your adventures and experiences. I am sure you will enjoy our website and forums. Good luck, stay safe and keep us posted.
Unplug the thermostat for about and minute and reconnect. Check for operation. If the thermostat does not light up, check for 12vdc at the roof top units. If you have 12vdc feeding the control boxes, check the fuses inside the control boxes. Verify you have good data cable connection a all the control boxes and at thermostat. Let us know what you find.

Traveling RN · 07-07-2014, 08:48 AM

I tried to reset the thermostat and unplugged it for a couple of minutes but still no power to T stat. I do have power to control box and the fuses are all good in the control box and fuse panel. My generator automatically started about the same time this quit working. I checked the breaker on the generator but no luck. Any help, thanks.

RV Wizard · 07-07-2014, 09:47 AM

Do you have 120 vac feeding the control board?
Is the 12 vdc clean; no ripples?

Traveling RN · 07-07-2014, 11:00 PM

I have 120vac to control box.

Pexring · 07-07-2014, 11:51 PM

Almost wonder if there's an issue with the cable to the thermostat? Might be worth checking continuity of all the cable wires if you can get the two ends close enough to the meter to do that.

RV Wizard · 07-08-2014, 04:23 AM

As Pexring has suggested lets check the data cable by taking thermoLook at the ends of the data cable used for the thermostat with the clip part of the connector like oriented (both up or down) and look at wiring color from left to right. Use a cable of same wiring pattern (straight or swapped). Sorry I can't remember which they use right now.