Forum Discussion

Carlos___Ranae's avatar
Dec 22, 2022

Thermostat issues

While working on the thermostat I accidentally touched some wires and there was a spark.
The fuses on the box for the thermostat and furnace are fine.

The thermostat does displays all functions, however, it will not turn on any of them.
Using a needle type tester there appears to be electricity flowing through the slots except the one labeled white.

Is there another fuse somewhere?

Our thermostat is a Airxell 9430.

Our unit is the Jayco Seismic 4212 toy hauler.
  • I don't think you'll get much traction on this issue as you posted it in Forum posting help and support. This page is for issues with the website itself. I think you want to post this in Tech Issues.
  • Remember, functions are also controlled by the roof AC control module. Jayco wired power 2 different ways over the years. 12 volt to supply the wall tstat AND the upper AC board from the hot side of the furnace tstat wires. The 2nd was 12 volt to the roof AC control board and then down to the wall tstat to power it. Doug
  • Carlos & Ranae wrote:
    While working on the thermostat I accidentally touched some wires and there was a spark.
    The fuses on the box for the thermostat and furnace are fine.

    The thermostat does displays all functions, however, it will not turn on any of them.
    Using a needle type tester there appears to be electricity flowing through the slots except the one labeled white.

    Is there another fuse somewhere?

    Our thermostat is a Airxell 9430.

    Our unit is the Jayco Seismic 4212 toy hauler.


    WHITE should be the 12 volt pos feed TO the furnace to activate it. When in furnace mode. Doug
  • i have a suburban sf-30 furnace that quit working. I replaced the mother board because i found a burnt part on the old one.I started the unit by crossing the blue wires (for the thermostat) and it worked fine. hooked up the thermostat(manual- not digital) and it did not make a sound. I turned it on a/c and it just hummed. i replaced the thermo, the furnace and a/c worked fine. after about 6-8 hours of the furnace running at a set 68ish degrees it stopped. the new thermo did the same thing as the old one, no furnace action and a/c humming. i went back to the blue wires on furnace and cross them and furnace worked fine . i thought i must have gotten to cheap of a thermostat, so i installed another one and it worked for the same 6-8hrs then nothing. I've got ground hog day going on.any ideas why my thermos are failing? they all had power to the thermostat as follows: 7.5v to the 7.5 post 8.1v to the cool post and 12.8v to the furnace post as well as all the others except ground.The furnace unit still works by crossing the blue thermo wires at the furnace unit!! new member/first time poster
  • KingBull wrote:
    new member/first time poster


    Welcome to the forums.

    Happy camping.