Roof Air Won't Come On

[StanJones]

We own a 2007 Mandalay with two roof air units (15,000 and 13,500 rear). Since we took the coach almost two years ago it has not worked properly. Recently I had a dealer tell me that the front unit needed a repair kit and 2 new capacitors. They were installed and I was told the unit was pushing cold air to beat the band.

Well I left the dealership after days of delays because we had to get on the road. Trusted that they did job right. Now on our way to Florida 3 days later we found out that the air was not coming on! We have two zones. The front zone has not come on at all since we turned it on 24 hours ago. Six hours after setting both zones at the same setting, the rear unit inexplicably came on at 10 p.m.! We hadn't touched anything. It stayed on all night and cooled fine. When we left the campground I shut off the electric at the pedestal in the campground.

When we came into the new campground tonight I plugged in the electric and then turned on the breaker at the pedestal and I heard the rear roof air come on ... but not the front. Three hours later, still no go for the front. I noticed that the control has a telephone cord plugged into the back of the wall control that must communicate with the roof air units. And also noticed the plug was part of a green circuit board (presumably the mother board) that communicates too to the roof air?

Has anyone experienced this? Or shed light on this. It's hot in FL and we will be there for the whole month of May into June. We'll need the air to be working!!! Thanks.

[shields]

Stan,

You indicate that something has not worked properly since you purchased the coach two years ago; is that something the air conditioning? If so, have the AC systems ever worked properly since you’ve owned the coach?

Once you left the dealership and started driving, you turned on both AC units, but neither one came on. Was the generator on and operating properly while you were driving? Were the other 120V appliances working ok? Was the control panel for the AC units illuminated? Let’s remember that the rooftop AC units require 120VAC power. They will not run unless (1) the generator is running, or (2) you are connected to shore power.

You indicated the rear AC came on about 10 p.m. I presume you were parked with shore power connected by then. Once the rear AC came on, did you check the AC control panel and try to start the front zone AC? Was the shore power 20, 30, or 50 amps?

It seems like the rear AC is working whenever you are connected to shore power. When you have shore power and the rear AC is working, try shutting it off and then using the control panel to change from “Zone Two” (i.e. rear) to ” Zone One” (i.e. front) and resetting the temperature. If the front AC does not come on, then you know the trouble is either the front AC unit or the Zone One control within the AC control panel. Depending on the outcome of that experiment, you might try the same test with shore power disconnected and the generator running.

I hope these suggestions help. Please let us know how things progress.

Good luck,

Tim

[garykd]

Gut feel says the dip switches are not set correctly for the front A/C unit. The dip switches are up in the roof A/C unit.