Thermostat on-off lever stuck

SOURCE: Dometic Rooftop RV Air Conditioner

Possible bad capasitor, or seized motor

SOURCE: thermostat wiring for second ac unit

I replaced one unite with another and the wires are differance colors the old unites wires are red,purple,yellow,bleck and white the new one have orange,brown,cream,darkpurple,and white

SOURCE: film advance lever.

Do you press the shutter button to release the lever for the next photo? That's how you advance the film from the exposure to light, when first insterting the film.

SOURCE: dometic ac in RV

The relay board is exactly what the problem was, thanks "Guest" The 12vdc relays are normally closed and before I replaced the board I was getting a 6vdc to 7vdc reading on the (cool) leg at the thermostat with the breaker off.

SOURCE: RV air conditioner. Compressor running, fan stops before cool

The fan motor is getting hot and going off on the internal overload in the motor.
This is caused by either a low voltage, a bad capacitor, or tight or dry bearings in the motor.
To check the bearings turn the power off to the unit, then spin the fan blade if it spins freely then the bearings are ok.
To check the capacitor you will need some kind of tester or you can buy a capacitor and replace it, that's what a lot of people do. They usually don't cost very much.
To check the voltage you will need a voltmeter and measure the volts at the unit.