[rvguy]

So the issue we found after extensive troubleshooting was.....
on the back of the rear six pack where the air line comes in, there is a small one way check valve in line right at the block where the pressure sensor lives. took out the check valve and BAM.  Coach works as It should. I took the six pack off, soaked in b12 for a few day, cleaned it all up. Rebuilt all solonoids ( thanks Tom). Bench tested system with 120psi and a good 12 v source. So at this time I think is all good unless, well lets just leave it to that.  Now if I can just get that rear slide to operate.

Thanks again everyone, Im sure this is a common issue from what I have been reading