Two air conditioners & two furnaces with one thermostat

When the thermostat was knocked off it may have damaged the wiring. I would start by checking continuity of all wires from thermostat to unit.

interior temperture sensor thermostat or communication cable.

try to jump the r and w where the t- stat wires are maybe bad t-stat

thermostat, cable or relay issue

For an RV 15000 BTU air conditioner the size being maximum for 115 volts ac you will need to have a independent circuit breaker for it only and rated at 20 amps. The average amps depends on serveral factors like actual supply voltage somtimes 110 to 120 volts and wire size and length feeding the air conditioner. To answer your question the average Amps will be near 13 Amps. Click Here=>

Dometic RV Air Conditioner Installation Manual and Specifications
Click here for a photo of the Electrical Spects.=>

Dometic_RV_Air_Conditioner_Electrical_Specifications
If you have any questions I will be here to answer them for you, Thanks, Sea Breeze

Just a guess, as I am not familiar with the solar assist, if the stat is wall mounted I would remove it and verify if there is wither standard batteries, or a "watch" style battery. hope this helps

If you look at control box at roof unit, they usually use a separate set of wires for furnace. See what colors they are attached to at harness to thermostat. Some just follow other harness, and come out at thermostat. (bypass control box) Once you've determined which 2 they are, join them together & see if furnace starts, as it should. If it does, thermostat is faulty. If not, pull outside cover off & check voltages at furnace. I'm guessing by furnace model that your unit is approx 30 ft , but if it's a park model, you may have 24 volt system on furnace or 12 volt. Another way of confirming is to go to back of furnace where air intake grille is inside your unit, and locate 2 blue wires going to furnace & remove whatever wires are attached to them & connect them together. Furnace should start up.

Check your furnace for power. will be 4 wires. power ground and 2 thermostat wires. Check for power at the time delay relay, if you have power there check for power going in the fan motor, if power in motor wire, motor is bad. If no power in motor wire and power going to circuit board take the 2 thermostat wire apart and wrap the 2 together comimg from the thermostat. Fan will stat in about 30 seconds. If it does you need a control kit in the ac. But sounds to me like you have a furnace problem.