I just moved into a double wide trailer with said Coleman furnace and I have turned the breaker off and on but the furnace still will not turn on I am not so savvy with furnaces so some help would be good. ( there is a black plug when I open up the door on it)

Can you test for power reaching the circuit borad or the tstat wire, tstat is probably 24 vac but the board gets 120 vac.

Can you test for power reaching the circuit borad or the tstat wire, tstat is probably 24 vac but the board gets 120 vac. How long has this unit sat vacant, is there what looks like a light switch on a metal box on the side of the furnace?