Rear AC won't turn on

Bronxj15 · 12-02-2021, 12:47 PM

Hello I have a Coleman-Mack 48000 series air conditioner unit in the front and rear of my 2020 27sgs cougar half-ton fifth wheel. The rear AC will not turn on and it doesn't have a knob it is operated through the in-command system. Any suggestions

wiredgeorge · 12-02-2021, 01:54 PM

If it doesn't have a knob, it may be controlled by a dual zone thermostat. Do you know how to find and operate the thermostat? I am not an expert on "in command" as I don't have this but seems you should be able to see the zone where the non working A/C is and turn it on from the thermostat. Good luck.

**JRTJH** · 12-02-2021, 01:55 PM

Did it ever work? I'd suspect that if it's a "new issue" that just started, the troubleshooting would be significantly different from if it's been like this since we bought the trailer and are just now getting around to needing the A/C, and found this issue.....

Bronxj15 · 12-02-2021, 02:54 PM

Yes it did work previously and recently has stopped working. The electrical issues start with my fireplace so I took it out fed an extension cord through the whole and plugged it into a working outlet as a temporary fix and put the fireplace back in. Then 2 of the outlets stopped working toward the rear of the camper, and after that now the rear AC will not turn on and it was previously working. Although it wasn't being used because the last few weeks have been quite cold.

snoobler · 12-02-2021, 03:35 PM

Quote:

Originally Posted by Bronxj15

Yes it did work previously and recently has stopped working. The electrical issues start with my fireplace so I took it out fed an extension cord through the whole and plugged it into a working outlet as a temporary fix and put the fireplace back in. Then 2 of the outlets stopped working toward the rear of the camper, and after that now the rear AC will not turn on and it was previously working. Although it wasn't being used because the last few weeks have been quite cold.

panel breaker tripped?

GFCI outlet breaker tripped?

**chuckster57** · 12-02-2021, 03:38 PM

Sounds like your trailer is 50A service, are the fireplace and rear AC on the same leg (side) of the breaker panel? You may need to check everything else on that side as you may have lost power. AC and fireplace should be on seperate breakers but maybe the same leg.

**JRTJH** · 12-02-2021, 03:46 PM

That was my initial thought as well... It sounds like you've lost one leg of your trailer main input AC power. I'd first start at the campground pedestal and turn the main breaker off, then back on. Move inside the trailer and do the same thing, then check that all the other branch circuit breakers are on. Do that by turning them off then back on because often times, a "tripped circuit breaker" will visually appear to be in the on position and it's sometimes impossible to tell for sure. So, turn them all off then turn them all back on.

That may "fix" your rear air conditioner problem... If not, then get back with us and we can go through resetting the In-Command system and further troubleshooting, but do the simple things first.

Bronxj15 · 12-02-2021, 03:51 PM

I checked the panel breakers and flipped them on and off just in case. Went outside to check the surge protector and no issue there but flipped the breaker for that just in case. The fireplace and AC breakers are directly next to each other on the rightmost side of the panel. This unit has 2 AC units the other one is on the left most side next to "solar"

Mike Honcho · 12-05-2021, 05:15 AM

If the Incommand display has -- where zone temp shows that means AC unit has no power at all. When it has power it shows the temp meaning the control board is communicating and sees the thermistor which is the zone temp sensor.

There is no thermostat. Just a thermistor going to communicating control board that gets setpoints and fan commands from the touchscreen.

bgrhrdt · 12-05-2021, 06:15 AM

In my Cougar, there is a panel in the front storage passthrough where you can operate things normally controlled by the InCommand unit in case it fails. I've never had to use it, but it's something I would check out.

ChuckS · 12-06-2021, 05:39 AM

Quote:

Originally Posted by Bronxj15

I checked the panel breakers and flipped them on and off just in case. Went outside to check the surge protector and no issue there but flipped the breaker for that just in case. The fireplace and AC breakers are directly next to each other on the rightmost side of the panel. This unit has 2 AC units the other one is on the left most side next to "solar"

As stated by others you HAVE LOST a leg of power into your power center panel..

IF YOU HAVE THE skills then remove the inside power panel cover and measure the TWO LEGS (RED WIRE AND BLACK WIRE) to see of each leg has 120VAC to it.. Repeat above process and swap meter lead from red to black wire with other lead on neutral BUS.. must see 120VAC

To measure each leg one end of the meter goes to the large RED WIRE and the other lead to the NEUTRAL BUS bar

Also - for reference to someone else post there ARE NO manual override controls outside on the BCM for any HVAC control

Miloski · 12-13-2021, 10:17 PM

What was the temperature in the RV when you tried to get the unit to operate?
Was in Idaho this summer and came back from a kayaking trip and the air conditioner would not kick on. I place a cold pack over the thermostat and when the temp dropped down in the low 80's the unit kicked on. This happened several times. I can let you know what was wrong when I pick it up tomorrow.

Bronxj15 · 12-23-2021, 12:56 PM

This was an issue and then when I switched campsites it appeared to resolve itself and the rear AC began to work. Now I'm at another campsite and the same problem is happening again the front will work but the rear won't. Seems pretty strange

**JRTJH** · 12-23-2021, 02:13 PM

Quote:

Originally Posted by Bronxj15

This was an issue and then when I switched campsites it appeared to resolve itself and the rear AC began to work. Now I'm at another campsite and the same problem is happening again the front will work but the rear won't. Seems pretty strange

It sounds like you're losing power to the affected air conditioner, probably at the power distribution center. If you have a multimeter, check the power "AT THE CIRCUIT BREAKER" to confirm that you have 120 VAC on the black wire attached to the circuit breaker.

wiredgeorge · 12-23-2021, 04:30 PM

Quote:

Originally Posted by JRTJH

It sounds like you're losing power to the affected air conditioner, probably at the power distribution center. If you have a multimeter, check the power "AT THE CIRCUIT BREAKER" to confirm that you have 120 VAC on the black wire attached to the circuit breaker.

Its likely easier to find a new campground and hope the 2nd A/C works than follow your tips on a 50A leg wire being loose in the power center.

**sourdough** · 12-23-2021, 04:43 PM

Quote:

Originally Posted by wiredgeorge

Its likely easier to find a new campground and hope the 2nd A/C works than follow your tips on a 50A leg wire being loose in the power center.

I think either issue may be the problem but if the OP is not having any other trouble other than the one AC, and it only happens when he moves the trailer, I would be thinking along the lines of something in that circuit. A power failure of some kind in the park would not make one AC work and then not work.

USFBullGuy · 12-27-2021, 06:44 PM

Mine was because the remote thermostat sensor was not synchronized with the on command system. I had to reboot the on-command by unplugging from shore power, turn off the battery connect for 30sec, then turn it all back on in reverse order.

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