[AlanJohnson]

Alan would have the SCS basement units.

Watch your ammeters at the front of the coach and have someone reset the breaker.

Does the breaker trip immediately?

Do you know how to use a clamp on ammeter?

Do you know where the control board is for the front AC?

Those answers will help us direct you to the next steps.

Well, it is something with the AC. It occured to me to turn off the AC and see if the breaker would reset.  It did.  When i turned the AC on at the thermostat i could hear something.... probably a compressor trying unsuccessfully to turn over.  It tried for a few seconds before the breaker tripped. (Earlier, the breaker was tripping immediately when the thermostat was calling for cool, and i was at the elec panel trying to reset the breaker.)

I have a clamp on ampmeter... and i've used it a couple times.  I am quite "fluent" with home AC repair/installs, but I haven't tried to dig into one of these units yet.  On a home unit, first thing I would check would be the capacitors, so if i can find these i assume i would do the same.  How much do I need to do to get to the guts of this unit?  Does it need to come out?

Thanks for all your answers!!
Alan