Two suggestions:: First if it is a trailer with NO Generator, and NO EMS (energy Management System, alas in these forums EMS has three meanings) then all you need do is replace the power cord and breaker box.. assuming the breaker box is not also your fuse box and inverter.... Fairly easy job.
Suggestion: Since the main issue seems to be the A/C....
Two suggestions: IF you have an EMS then find the wire from the EMS relay board to the Air Conditioner,, REMOVE it and rout it to a Junction box.
Run 12ga wire from said J-box to an INLET (This is a plug like device) or .. Well read on for what I used.. A 20 amp type would be best.
Run a 20ga lead from the original connection point on the EMS to an OUTLET
NOTE: Mount these inlets and outlets in an outside compartment in a weather protected space!!!.
Plug the outlet onto the inlet or the inlet (Plug) into the outlet for NORMAL operation.
If you need, as Tim Allen used to say on Home Improvement "MORE POWER"
Unplug the A/C from the outlet and use a 12GA extension cord to the park's 20 amp outlet.
NOTES:
A paranoid (And that includes me) Would want a 20 amp breaker on the back side of that inlet.. But though I am Paranoid, I trust the park's breaker.
Second.. I took a 12GA extension cord (Sears/K-Mart/Home Depot/Lowes/Menards and many good hardware stores) 2x the length I needed to get from the J-Box/Breaker box to the outside compartment where I parked it.. Cut it in half and used it.
NOTE: 2: SOLDER the junction, works better, you will need a good size gun or iron to solder 12ga wires, My little iron was not up to the job (My big gun was). I melted a junction when I just used a wire nut in the J-Box.
Finally.. If you do not have an EMS.. then it is easier, You simpley disconnect the wire from teh A/C Circuit breaker and wire it as above.
There used to be a company "Power Solutions for RV" (psrv dot com) But alas I have not been able to see their web page for a few years. This is basically.. Their design.
