Forum Discussion

Hemling's avatar
Hemling
Explorer
Jul 03, 2022

Random a/c issue fixed?

I have been having a random A/C problem for the past year or so. A/C will function normally, but thermostat will turn off with no warning. Sometimes it comes back on, sometimes not and you just have to wait until it decides to turn on. It is hard wired - no battery. I replaced the thermostat and did the same thing. We are in the middle of a cross-country move from Miami, FL to Northern Wisconsin, and it has really been acting up. Broke down and called up a service call tech in the middle of Alabama and he found the thermocouple had fallen out and was dangling in the center of the roof unit. He plugged it back in and since then the A/C has not stopped working again. Does this sound legit? I mean, I've got floor issues and other items coming up for the winter hibernation that I don't feel will be cheap, so I don't want to jinx myself that I've avoided a possibly expensive A/C issue also, but crossing my fingers. . .
  • dougrainer's avatar
    dougrainer
    Nomad
    Jul 03, 2022
    Hemling wrote:
    Yes - that is my thermostat. Since I have 2 (probably good) thermostats, my plan is to wire the second one directly to the upper unit if it cuts out again. So far, so good though.


    Forgot to mention from first post. That Freeze sensor that was hanging. The ONLY thing it would do is NOT keep the evap from freezing. No other operational problems will happen with it dangling. Doug
  • Hemling's avatar
    Hemling
    Explorer
    Jul 03, 2022
    Yes - that is my thermostat. Since I have 2 (probably good) thermostats, my plan is to wire the second one directly to the upper unit if it cuts out again. So far, so good though.
  • dougrainer's avatar
    dougrainer
    Nomad
    Jul 03, 2022
    Hemling wrote:
    It is a Coleman Mach. It is a digital display - very basic 3-button unit nothing fancy. Sometimes the A/C would shut off and the display stays on and you can just turn it back to 'cool' but other times the entire thermostat would go dark and there is nothing you could do. In my attempts to fix it I replaced the thermostat with another identical unit and it still did it. Also, jumping power to A/C and high fan does nothing (no power to thermostat at all) when it goes totally dark.


    What you are describing is a wire problem between the Wall tstat and the upper unit. Either the wires are loose or corroded at the upper AC unit, or there is a fault in the wire bundle from the Wall Tstat going to the upper AC unit. Click the link. Is this what your tstat looks like? Doug

    https://www.rvupgradestore.com/Coleman-Mach-Digital-Wall-RV-AC-Therm-BLK-Plugs-p/41-0061.htm
  • Hemling's avatar
    Hemling
    Explorer
    Jul 03, 2022
    Yeah, Miami is getting a bit too expensive. It was fun but time to slow the pace of life down a bit.
  • Hemling's avatar
    Hemling
    Explorer
    Jul 03, 2022
    It is a Coleman Mach. It is a digital display - very basic 3-button unit nothing fancy. Sometimes the A/C would shut off and the display stays on and you can just turn it back to 'cool' but other times the entire thermostat would go dark and there is nothing you could do. In my attempts to fix it I replaced the thermostat with another identical unit and it still did it. Also, jumping power to A/C and high fan does nothing (no power to thermostat at all) when it goes totally dark.
  • midnightsadie's avatar
    midnightsadie
    Explorer II
    Jul 03, 2022
    that would cause false readings. good luck. wis inlaw had a cabin on teel lake. at night we used to practice duck hunting used mosquitoes for targets.you do know they are the capital bird? loved it up there have fun.
  • dougrainer's avatar
    dougrainer
    Nomad
    Jul 03, 2022
    You need to state Brand and Model of AC unit. The "thing" dangling is most likely the FREEZE sensor. There is NO so called thermocoupler in a AC unit controls. Is your Tstat LED? You lose display when you state it turns OFF? Or it goes from AC cool to OFF and display always stays on? Really need to know Brand and Model of AC. Doug

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