Intermittant A/C

I have the exact same system. Same problem with the afternoon sun.
Put the thermostat in high or low for a few hours until the sun gets lower and problem is solved. The system is trying to settle on low speed but then the rig warms up and it goes back to high. It takes about 5 seconds for the motor to change speeds. It does cycle from low to off and then to high.

Mine did this mostly on cooler mornings. It thinks it needs to cool,but gets confused. Repositioning the thermistor in the airflow has been suggested. I got a Coleman.

The fan speed upshift and downshift is normal and depends on whether the room temperature is within four degrees of target temperature. Over four, it goes to high. Within four, it goes to low.

"It is almost like the rig is getting a drop in voltage"

WHY I have a surge guard (well one of several reasons)

Advantage. Both the TRC/Southwire Surge gards (Which is what I have due to a fantastic sale price) and the Progressive Industries EMS units the remote (Optional on the TRD) for the hard wired or the display for the plug in shows both Volts and amps on both lines of a 50 amp (just one on a 30).

Now.... Mine has protectd me against (So far)
High voltage (There is a weak neutral on the sight I'm on now)
Short term failure (Like one or two seconds)
Open Ground (Park had to fix that one)

Just to name 3 conditions the unit protects. Low voltage is also covered one and open neutral.

Plus.. No matter what folks tell you there is a 240volt outlet that looks a whole lot like a TT-30.. and in fact a TT-30 will plug into it.. That's covered too.. I've never done that (yet) but I have seen one such outlet.... (I had to look for it someone told me it existed but I already knew it was 240 volt)
(He called it 60 amp, in the breaker box were two sets of 60 amp breakers, both ganged, so I knew the 60 amp outlets were 240 volt).

I had forgotten I had posted this back in April when we last used the 5'er. On this trip, our first one since April, the same thing happened. I had not thought about the electric hot water heater and the refrig pulling amps. Both are on Electric. This particular campground is old and only has 30A at the pedestel. I haven't checked it yet but I will bet its getting hot. Because it tripped out earlier and I reset it and it tripped out again shortly So I let it sit off for 30 min or so and it seems to run ok. But, off goes a few electric items when I use the AC. Plus I will have it checked when I take it in.

I doubt this is your issue but.. it might be.

When my Rig was new and I mean NEW sometimes one A/C would work, Sometimes Both, Sometimes the other, Sometimes neither.. I decided to Tribble shoot before returning to dealer.
First stop was the main breaker box (Power distribution panel is the proper name) and one of the screws holding one of the wires took over THREE FULL TURNS to tighten down.

A/C's worked perfectly after I got rid of my loose screws.

Is this the Dutchman Denali 5th Wheel ....
if so it uses an Atwood water heater

Here is the Wiring Diagram



Electric/Propane use SAME DC Supply, same t-sat/eco, same thermal fuse....so if AC element is heating then that rules out all of the above

That leaves the Circuit Board transformer (supplies High Voltage) for ignition and/or Spark Electrode (wire/connections/ground

Not saying this is your problem but many RVers have few screws loose.

When My Damon was "Sticker in the window" new sometims one A/C worked, sometimes the other, both or neither. I decided to tribble shoot before I took it in. Opened the AC-Distribution panel (Also known as breaker box) and one of the screws took 3 1/2 turns to tight.. Several others were loose as well.

NOTE Unplug from shore power. NO running of generator while working by 12 volt light (house light)or flashlight in that box..

But that's step one....

Two things about this advice
1: Your free is cheerfully refunded (the ultimate money back guarantee)

2: those screws. if loose, are a fire hazard. If tight, they are not.

dougrainer wrote:

jdc1 wrote:

rockcandymountain wrote:
My Dutchman Denali 5th Wheel has a Dometic Roof Air Unit

Almost all of the time, it runs just fine.

Every once in a while, it will shut off and restart at what sounds like a slower fan speed. Then after a minute or two it will shut off again and restart at normal fan speed. Its almost like the rig is getting a drop in power from the pedestal but I have no way of checking that.

That's not good. It will eventually burn up your unit. Unplug the converter. This will allow the AC the full incoming power (your converter cycles as needed).

Explain your reasoning behind this statement. The converter only pulls at max about 3 amps. If you unplug your converter, then your RV will go dead from the battery going dead after a few days. The Converter has NO BEARING on RV roof AC operation. Doug

Actually in my last trailer that's exactly what I had to do to get through a 4th of July weekend where the park had very low voltage, turn off the converter during the day as that kept the voltage just high enough to not trip the EMS. I flipped it on before going to bed and off in the morning. Also ran the fridge on propane the whole time.