Well, I got one of those intellitec thermostats ( which i had refurbished last year along with the ECC relay), and its supposed to be able to cyle both, but, alternating the compressor ( their not supposed to be running at the same time)s. After painstakedly tracing hand over hand the power feed from my home panel to and in the rv. It was hell getting at the feeds for the power distribution center, all good, terminals all good, I removed each breaker and inspected the bus bar, all good, no tale tales of arcing, and removed every fuse and checked continuity ( All Good), terminals are tight. So I ran the onan in the off chance I was having a shore power amperage issue. Made no difference, compressors try to start as on shore power, then locked out. Low and high fan run like "scaulded dogs", but the compressors dont have the ummhp. So next step is on the roof to check the capacitors, and to see if anything Has tried to make my RV its house too! So the search goes on.