Apparently, 04 coaches do not activate the hydraulic fan when the dash AC is on. In some cases, where engine controls do not call for fan operation and the condensing coil (stacked by the radiator) needs air flow and doesn't get it (e.g low coolant temp, idle & stopped, hot ambient temp), the AC system can overheat and take out the AC compressor and expansion valve. It happened to me.
I understand new engine controls addressed this on 05/newer, but I don't know if 03/earlier have this issue. I recall some earlier units have a separate "AC on" switch that probably activates the fan. To check, start the motor (cold), turn on the AC and look to see if the fan is operating.
WRV has a kit comprising a solenoid and hydraulic valve to activate the fan.
If you're in the warmer climates, using Dash AC a lot, it seems to me that sooner or later the system will overheat and fail.
Rex Ames and Mark Hara at WRV were very helpful and responsive dealing with this issue.
2004 Alpine 34 FDDS
Anaheim Hills, CA