Where is the thermostat?

[rgcanoe]

Hi
I have a 2012 3400rl Montana fiver. I have one A/C unit existing, installed and ducted through the unit. That thermostat is by the stairs. I am installing a prewired, non ducted one in the bedroom. The power wire was in a box by the unit opening. There is a small cable (communication wire) hanging out a hole in the framework,, which goes to the thermostat. However, there is nothing to show where the other end is.
I would assume it would be near the other thermostat, so they could (maybe) be a duel stat?
I looked behind the old stat and there is only one cable place on it and it works the rear unit. Where would they hide it???

Rolland
Full timer
One camper in Crystal River, Fl
One camper in Sea isle city NJ

[ChuckS]

If your existing thermostat is a multi zone thermostat then only telephone cable to it ..comes from original AC unit control module

The other end of that second AC you are adding on would then most likely be located up inside the existing AC unit usually located underneath the exterior cover on that AC...

Thermostat ... if it’s capable would then communicate across the CANBUS that runs from thermostat to zone 1 (original AC) to zone 2 (AC you added)

Dip switches on both AC units control module box or gateway would require proper config..l

If existing thermostat isn’t multi zone capable then you will need a different thermostat.

[Skw774]

Ours is just inside the bedroom door on the left

[rohrmann]

Most likely, you have one of these above your panel that's under the existing A/C unit. The special 'phone' wire that goes from the thermostat plugs into the box circuit board for the existing A/C. from that box to the new A/C, there should be another 'phone' cable, and that should plug into the same box which should be installed when you install the new A/C so you can control it from the same thermostat. The box is at this link: https://www.amazon.com/Dometic-33120.../dp/B00HSO05R4


To make this work, you will also need a remote temperature sensor, which may also be installed already. https://pantherrvproducts.com/dometi...rature-sensor/ Ours, which was factory installed in our rig along with the factory installed A/C, is mounted in the ceiling of the bedroom, and it connects to the box to be installed that is in the link above. In the box, there will be a dip switch which identifies the new A/C for the existing thermostat, so you can control the A/C. This manual will explain the installation instructions: https://www.dometic.com/assets/12/75/3315085_71275.pdf


Good luck.

[rgcanoe]

Bingo....... The two units are "in series"
I need to look inside #1 to see if I have two incoming.
Thanks

[rohrmann]

Originally Posted by rgcanoe

Bingo....... The two units are "in series"
I need to look inside #1 to see if I have two incoming.
Thanks

You should be able to remove the filter and see the metal box, and you might be able to take the cover off if you can't see two phone type cables without it off.