Digital thermostat

[Wild Horse]

I've seen some wiring diagrams for changing over these pos thermostats to digital ones...I picked up a digital thermostat and wired it, but couldn't get just fan to work, nor the high fan ? No, I didn't wire a separate switch to the high side...I have no need for the low side, so I wired the high direct.

li'l help here please ?
Bill

[racerjoe]

it could be in the control unit inside the air conditioner housing. When we switched ours over to the Comfort control unit we needed the unit inside the a.c. to make it work correctly

[jpbcny]

To have just "High Fan" you need to connect both the Orange (Low Fan) and Blue (High Fan) wires to your Digital Thermostat Fan Terminal Normally "G".

The Diagram below shows an optional SPST switch so you can have either fan speed, but to have "High Fan" only, connect both fan wires to the "G" terminal...

JP

[Clemson1881]

The low fan is necessary if it's not too hot outside, but humid. The high fan in moderate temps will cause the unit to short cycle and it will not remove enough humidity before it knocks off. The low fan will let the unit run longer before the set temp is reached and in doing so will remove more moisture from your rig. Some of the newer thermostats have "auto" fan which chooses high or low for you depending on how far above the set temp it is.

[Wild Horse]

Thanks for the replies !
I'll have to wait until next week when it's hooked back up to shore power.
Bill

[Jdrobone]

Excellent advice Clemson. Lot of people don't realize that AC's are better slightly undersized than oversized anyway.
Jerry

[5ER]

When I added a digital t'stat on our old 5th wheel I had to drill a small hole in the side of it to add a small toggle switch for high or low fan.