Welcome to the forum
2X, on what Vince has said. If you have a stand alone converter/charger, then , depending on the output , they run $175 and up, and I replaced mine in 20 mins.
If your coach is equipped with a combination , inverter/converter/charger, then they cost more and install time goes up, but depending on access to the location , shouldn't take more than an hour.
But you do need to be sure you need one first, model number, and owners manual for testing , because they do have fuses or circuit breakers that need to be checked before you go to far.