RV Products A/C not coming on

I have an RV Products heat pump (A/C) model 6535A871 in my 2003 Itasca Horizon Diesel Pusher. It has been working fine until today. Yesterday I changed the coolant in my generator thus I had to put load on the generator several times during the drain, flush, refill, etc. stages so I used the A/C to do this and it worked fine. I ran it off and on for well over 1 hour with no issues.

Today I started my generator (worked fine) and decided I wanted the A/C on. It was almost 80 degrees F outside. I have a TrueAir Residential Control thermostat/control unit. It showed the ROOM temp to be 77 deg. F. The Fan Mode was in AUTO, FAN SPEED set to low. I clicked the control over to COOL and then pressed the SET TEMP BUTTON to 65 deg F just to get things running. But nothing happened. I was able to switch the fan over to MANUAL ON and it came on fine but the compressor would never turn on. It is a "basement" unit and nothing in the unit ever seemed to come on. The outside fan on the unit never came on.

I'm baffled because it worked great yesterday and now suddenly this. I checked to make sure my circuit breakers were ON and they all were so nothing had tripped.

Any ideas, thoughts, experiences would be appreciated.