Air Conditioning on Monaco Coach

I have a 2003 Monaco Executive with three heat pumps on the roof. Intermittently they will not cool the coach when in cooling mode. When this happens they typically all will not work. I switch them over to heating mode and they come on and work fine. This happens when using the generator as well as shore power. There are two thermostats. One in the bedroom with two zones and one in the living room with one zone. Every indication is that they are OK. I even tried swapping them, to no avail. Als

My solution to this same problem was to dump the flourecent tubes (and their ballasts) in favor of LED tubes. Pricey, but brighter and much longer lasting. Another possible cause of electrical issues is a failing "salesman's switch" relay in the engine compafrtment along with the battery isolator in my '01 Monaco Exec. I was having flickering lights and HVAC shut-down due to contacts in the relays dying. I dumped the relays and house DC is wired directly to the 12v house bus in the same compa