Buster83

I have a 2002 Monaco Knight. When I first bought it, used, the AC had reverted to its default status ( flowing through the defroster vents). I found that the vacuum pump fuse was blown. After a year and a half, the system went to default again. The fuse is good. I think there must be something wrong with the pump or wiring to it. I can not locate the vacuum pump. Please help!