Forum Discussion

azbohunter's avatar
azbohunter
Explorer
May 04, 2018

replaced my Dou Therm stat with digital

I followed this video pretty much but wires were different colors. If you jump to the 3:45 spot on video is what I am referring to.
Like this
Everything works fine except I can not figure out the high and low speed fan operation. I have not installed a switch as shown here (yet) but I have a orange wire which was fan on Dou Therm and blue wire which was low fan. On the digital there is only "fan", if I hook the orange to it I have fan on high speed, if I disconnect the orange and hook up the blue I have no fan. (I would think this should work) in the video attached and several others I have watched they added a switch to go from high to low but if hooking the blue wire to fan on digital stat (with no luck) how is the switch going to work different? Maybe I am just confused??

18 Replies

  • azbohunter's avatar
    azbohunter
    Explorer
    May 07, 2018
    Old-Biscuit wrote:
    Thank you for the 'details'

    And that is exactly why I never bothered with installing a switch for the fan speeds.....just hooked up Hi Only


    :);) But the challenge?
  • time2roll's avatar
    time2roll
    Nomad
    May 07, 2018
    The Dometic single zone digital has limitations but does have fan high, low & auto settings.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    May 07, 2018
    Thank you for the 'details'

    And that is exactly why I never bothered with installing a switch for the fan speeds.....just hooked up Hi Only
  • azbohunter's avatar
    azbohunter
    Explorer
    May 07, 2018
    Old-Biscuit wrote:
    azbohunter wrote:
    Thanks to all that added any thoughts to my fan issue. Between what everyone has suggested, I have it working. With the themostat cover off it was simple enough to take a jumper wire and go from power to wires and it was easy enough to figure it out then. I think I have it now, just need to wire in a switch, I think. What I find humorous is that I remodeled and rewired our house 6 years ago, no issues, but I was drawing a blank on this one:(


    Details Man...come on details

    Why did't it work before (Lo Speed)?

    Old-Biscuit,
    I hate to embarrass myself on a public forum but, this is what I found. "Obviously" my hearing at 74 is not what it used to be and "apparently" when I had it hooked up in trial mode, I was getting both hi and lo, but because they are rather close and I could not switch from one to the other with the thermostat cover on, I was believing I was only getting hi. When I used a jumper wire with the cover off and jumped from power to fan or power to fan lo, it was like "****, it's been working right all along". So, I had to laugh at myself. My wife has been telling me my hearing is not so good at times;) So now you all know. :S
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    May 06, 2018
    azbohunter wrote:
    Thanks to all that added any thoughts to my fan issue. Between what everyone has suggested, I have it working. With the themostat cover off it was simple enough to take a jumper wire and go from power to wires and it was easy enough to figure it out then. I think I have it now, just need to wire in a switch, I think. What I find humorous is that I remodeled and rewired our house 6 years ago, no issues, but I was drawing a blank on this one:(


    Details Man...come on details

    Why did't it work before (Lo Speed)?
  • azbohunter's avatar
    azbohunter
    Explorer
    May 05, 2018
    Thanks to all that added any thoughts to my fan issue. Between what everyone has suggested, I have it working. With the themostat cover off it was simple enough to take a jumper wire and go from power to wires and it was easy enough to figure it out then. I think I have it now, just need to wire in a switch, I think. What I find humorous is that I remodeled and rewired our house 6 years ago, no issues, but I was drawing a blank on this one:(
  • azbohunter's avatar
    azbohunter
    Explorer
    May 05, 2018
    Ron3rd wrote:
    Others on this forum have done the conversion and needed to add a small toggle switch on the side of the t-stat to control the hi-low fan functions.

    Others that have done it can give more info.

    FWIW, I believe all the major RV A/C mfgs now make digital t-stats that can be simply retrofitted.


    Hi Ron,
    Thanks for the input, I have scoured the internet and looked at many YouTube videos, it hasn't helped me. Honestly, I am really pretty good at this kind of stuff and can usually figure it out eventually, not sure about this one. I have walked away from it for the time being hoping that when I look at it again, it will be clear. I have the Honeywell thermostat from a remodel so I had no cost in it, everything works great and temp holds within a couple degrees without the be swings. Except for the lo fan speed..:?
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    May 05, 2018
    Others on this forum have done the conversion and needed to add a small toggle switch on the side of the t-stat to control the hi-low fan functions.

    Others that have done it can give more info.

    FWIW, I believe all the major RV A/C mfgs now make digital t-stats that can be simply retrofitted.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    May 05, 2018
    Pic shows OEM wiring BLUE/Hi Fan and ORANGE/Fan

    IIRC have to have BOTH for Lo Fan

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,255 PostsLatest Activity: May 24, 2025