Looks like I'm the first person with this problem so I'll put my limited repair skills to work. I tested the thermostat voltage outputs per duo-therm troubleshooting guide, all voltages good. Also removed the A/C cover to gain access to start and run caps. Next will order and replace those, also purchased new Honeywell digital thermostats which will replace the analog types. I'll post results when complete.
Also as I checked more systems, seems the front furnace joined the ranks of failures. Nothing happens when I ask for heat except a fuse is blown as soon as I select heat. Don't you just love these older RV's, especially when dealing with top secret schematics as Gulfstream owners have discovered. This will be the next project after A/C problem.