Paul,

I forgot to mention the blower motor might not run because the brushes are worn. According to the prevost spec they should be replaced at 3/4" of length. If the CB has not tripped, but the blower motor isn't running, check the brushes. They are easily removed, although access to the ones in the rear are a little tricky.

I wrote an article once that may be listed under information sharing about the brushes.

I also check all the relays for open circuits.

Jon