Help! No pwr to thermostat 30DS

[Goofy1]

Help, we are in Indianapolis for our first cold night of camping. And everything seems to be working except that the Thermostat has no power to it! I’ve cycled all the circuit breaker’s and checked the three fuses that seem to have anything to do with it. Still no luck. What’s next?

[mwdilday]

Everything else is working? If so you have 12v power. Only thing I know to do is pull the cover on the thermostat and check the voltage to it.

[Goofy1]

We made it through the night but still no power to the thermostat.

The thermostat is a combination unit shown in the manual in the Atwood a/c installation. Is there a fuse in the thermostat itself?

We switched power plugs this morning and checked more fuses but still no luck. Any and all suggestions welcome.

[Carl17]

The last time we had no power to thermostat the no. 7 fuse 12 volt in panel was blown . Pull fuses out and check or us volt ohm meter. Not a 100 % sure on number but its in the 12 volt box. check them all.

[TheWolfPaq82]

As mentioned, you need to open the thermostat and see if you have any voltage to it, then work backwards from there.

[Roadhouse]

Ours was a fuse for the air conditioner. The furnace switching is run through it.

[ceedog]

Did you check to see if the thermostat was turned on? There should be a switch on the bottom of the unit.

After that a voltage check would be my next check since you've cycled the breakers & checked the fuses.

Be sure to check every compartment for fuse boxes not mentioned in your coaches literature. In my Berk, there are additional fuse boxes in the coach battery compartment that control a lot of circuits in the back of my coach. They're not mentioned in any literature associated with my coach.

Let us know what you find plz.

[antilley]

My bet is the fuse at the foot of the bed is tripped ....

[Goofy1]

Thanks for all the suggestions. We made it home and used a portable heater to keep the chill (mostly) off. Our night in Michigan was at ~34 deg F.

I'll start a more indepth evaluation and post back when I get it figured out.

Thanks again!

[Goofy1]

We got home and took the stuff out of the fridge and our clothes in the house. Finally get back to clean and work on the RV. Start up the generator, push the on/off button on the thermostat and it fires right up!!!! Switch over to heat and the furnace runs like brand new.

To review, on a 30DS the shore power plug is used to plug into the generator output.

The only difference is that I was running on the generator not shore power and I didn't have the jacks down. Other than that everything else was the same.

Suggestions or ideas welcome.

[Carl17]

The furnace runs off 12 volt side so you can boondock. So it will run with out shore power or gen, But the house battery switch must be in the on position. So not sure whats going on could be a loose connection?

[Goofy1]

Thanks Carl. Does your FR3 have the digital thermostat? Ours is a 2017 and has a thermostat like this:

https://rv-pro.com/sites/default/fil...thermostat.jpg

I'm going out and try again today to see how to get the furnace to work on batt power.

[GeorgetownJeff]

The tstat gets it's 12,vdc power from the AC. If you pull the tstat off the wall, there will be 4 wires there. It's been awhile, but I believe it's red, black, blue, yellow. Red and black are your power wires (you should have around 5 vdc there). The other 2 are communication wires, don't worry about them. If you need more help, call FR3. 574-606-7600

[Carl17]

Yes have same one. We got a new Atwood Ac unit two years ago and they upgrade Thermostat to that Digital one,that one.

[Goofy1]

Thanks to everyone. I learn more everyday about my FR3!

[Edmo]

The breaker may have tripped

[Goofy1]

Well, after working for a couple of weeks when I would randomly test it I'm back to square one today. No pwr to the thermostat, no lights, no signs of life. I did as I have been doing and cycled the Chassis Battery switch by the door off then on. Went to the thermostat, pushed the on/off button and nothing!

My gut feeling is that there is a relay somewhere in the 12vdc line from the batteries to the thermostat that is not releasing. Where do I find a wiring schematic for my coach? If I could get that I'm pretty sure that I can chase the wires.

Thanks to all.
Garth

[GeorgetownJeff]

The thermostat gets it's 12 vdc from the control board in the AC. There is a 12 vdc input on the board and a 4 pin connector out for power, ground and communication. I believe there is a 12 volt fuse in your panel for AC.

[Carl17]

There could be a broken wire to the thermostat which i believe comes from A/C unit Or A/c unit has a bad controller board. Has far as wiring try Calling Forestriver or dealer. Also search this web site.

[Goofy1]

Determined to find the problem I removed the thermostat and the splice to the red power wire was holding on by a thread. I had to enlarge the hole where the wires come through the wall to fish the wire through and replace the splice. Turned the power back on and (hold the applause) the thermostat WORKED!

For the owners of the 30DS know, the thermostat sits slightly behind the slide. So there I am enjoying the furnace running smoothly and I engaged the slide to get better access to the 2 screws in the back of the thermostat. And that's when it died!

So today it is supposed to be 65 degrees and I'm heading out to see if the thermostat wires are tangled up with the slide wiring snake. Not exactly sure how to gain access to that area for the wiring but worst case I'll cut a hole and patch it with a piece of luan.

Keeping my fingers crossed!