If the A/C is original to the trailer, it may well be best to replace it entirely. Yes, costly but you can get the Rec Pro unit that has built in soft start and very quiet running, lower profile and low amp draw, and probably be much happier than the old stuff on there now. If the old unit only needs a capacitor or something simple, then spend the money, but if it has leaked that means a line is probably broken (they are sealed like window A/C units) and at that point the money is best spent on a new unit.
https://www.recpro.com/rv-air-condit...ol-non-ducted/
Post up a pic of the taillight. is it smashed, broken? Generally the Bigfoot uses Bargman
lights, series 84. if the lens is cracked or smashed I would get two of the LED replacements and install them.
Two screws, out with the lens, out with the bulb, coat the new connection with dielectric grease and plug it in the socket and put the two screws back in.
Bargman 47-84-410 LED Upgrade Kit for #84 Series Light - Red this gives you brake & turn plus running
lights. The entire black frame is available if you need it but no sense replacing it if it is not needed. Now on mine, the LED is hardwired as it came from the factory but I replaced the backup
lights as you can see, it used the bulb base in the socket to make the connection, however I had to add reflector to replace what was lost on the backup
light conversion. The reflectors were added after the pic was made, red rectangular ones below the taillights, plus the DOT tape on the bumper. First pic has solid red tape that was crap so I removed it and installed the red white tape that is impressive. I used Grote plastic reflectors under the taillights.
Charles