We had this problem and the fault was in the time delay circuit board. To test this you have to open your transfer switch and flick the tiny dip switch to by pass time delay. If you get power to your coach from genny after doing this, the next step is to replace the circuit board ( its very cheap ). You can use your generator in by pass mode but you wont have any delay. I would turn main breaker off, start genny, wait a minute or two and then put breaker back on. Did this for a couple of months before replacing circuit board.