What is your incoming voltage?
If it is very low (less than 110), the AC and fan motors starting up at the same time:
1) may draw more amps than your current service can supply in hot weather. This could be a campground issue.
2) The high amperage draw of the AC compressor motor trying to start with low voltage may be triggering its thermal cut out switch. It will try to start again until it cools off.
When the fan is already running, the lower amp demand of the fan motor may be enough to sustain the voltage while the compressor motor starts.
MAKE SURE YOUR WATER HEATER IS ON PROPANE and NOT 110 AC.
In extreme low voltage situations, you may also need to switch your fridge to propane as well.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW