I recently did a Dometic analog to digital thermostat replacement and want to share the install. It was an easy install once I got the old control box out and organized the wires.
First, turn off the main breaker and the battery disconnect to cut all power to the AC unit. There is a 12 volt supply to the control box, so be sure to kill all 12 volt power.
The digital control box(right) is smaller in size than the analog box(left), but resides in the same brackets.
Cut the tstat wires, 12 volt wires, and heater wires. Unplug the AC control wire bundle, freeze sensor, and disconnect the 110 volt supply. Remove analog control box.
Remove the old freeze sensor and replace with new supplied sensor.
New(left) and Old(right)
Press new sensor into fins one inch from bottom (I put mine on the lower right looking toward rear of RV) and gentle bend fins around sensor to hold into place.
Connect the 110 volt supply to the digital box, matching wire colors and using wire nuts.
Find the two heater wires and attach the supplied spade terminals. The heater wire in this RV is a two wire cable consisting of a red and white wire.
Affix the digital box to the bracket on the AC unit with supplied screws.
Plug in the AC control wire bundle
Plug in the heater wires
Plug in freeze sensor.
Remove analog tstat
The digital tstat only uses three of the seven wires of the tstat cable. I choose red, white, and orange to match the color wire at the control box.
Connect the three wires.
Red: 12 volt positive +
White: 12 volt negative -
Orange: Common or communication
Before attaching tstat to the wall, be sure to cover hole is wall where the tstat cable protrudes. This will keep hot air for escaping wall cavity and give the tstat a false reading. I used some insulation and covered with foil tape.
More on next post.........