Coleman Mach A/C questions

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Sierrali

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Joined
May 6, 2021
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5
Location
California
Purchased 2021 destination trailer with two Coleman MachA/C units. The air is cold. But the air is blowing from the side that has the filter on it. And pulling in air from the side that is meant to blow air. (The side with vents that open snd close). I put a dryer sheet up to it to verify that I wasn’t crazy. It did indeed get pulled to the side that should be blowing air. Why is this? Is it just that the cover is on wrong and needs removed and spun 1/4 turn? It is like this on both a/c units. Also, I have no air flow from any of the ceiling vents in the trailer.
 

OldMarine

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Apr 30, 2020
Posts
60
whoa...it kind of sounds to me like your fan motor is running in the opposite directional rotation than it should be.. if the " squirrel cage" blower fan is spinning reversed, it would pull air in and blow out opposite of what it should. Might want to check the fan motor for reverse polarity?
 

Jaycomlok

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Feb 2, 2020
Posts
53
Location
NW Arkansas
Sound like to me the blower motor was installed backwards. In other words wrong shaft out wrong side. Unless you have a RV blower motor I've never seen in your ac unit there no way of reversing the direction other than turning the motor 180 deg which reverses the shaft direction on both sides. One other thing you can check is direction the air is moving across the ac coil on the roof. You should feel a lot of air blowing out the back of the unit if correct.
 

Sierrali

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Joined
May 6, 2021
Posts
5
Location
California
My trailer is very high and I don’t have the ladder needed to get up there today. But the wiring of motor blower ( if it had one) and the backward installation of the motor are two places to start. One thing that did happen, which is what got my attention in the first place was that the a/c unit in the loft sounded like it was on, but when I climbed into the loft, the room was warm and warm and unit was not blowing air. I went to thermostat to turn it to “off” position. And i could still hear the unit running, but not a blower on. So I slowly went through each setting (fan lo, fan high, cool low, etc) and made sure the system changed to each setting. And it did. So when I changed it to “off” mode, the system shut off. My daughter swears the air was blowing correctly prior to this incident. She would always close the vents when she got to chilly so she should know what she’s talking about. That is when I went to test the a/c in the main area. It is a high ceiling so I’ve not been able to notice what direction air was blowing from prior to this. But it, too, is blowing in wrong direction. So I’m very confused. I guess I’ll start by finding an RV a/c service tech.
 

Sierrali

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Joined
May 6, 2021
Posts
5
Location
California
Not yet. However, we are 3 hours away from the dealer. The warranty requires the trailer be taken to them for repairs the first year. And since this purchase was out of necessity (lost our home in a wildfire) we are not in a position to unpack it and haul it 3 hours both ways. It’s currently our permanent home.
 

Rene T

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May 20, 2011
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17,285
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Farmington NH
1st, welcome to the forum. Sorry to hear about your situation.

Contact the dealer and see if you can get them to approve of a mobile repair mechanic to come to you to look at it. They may have to contact the manufacturer. Explain your situation to them.
 

Sierrali

Member
Joined
May 6, 2021
Posts
5
Location
California
I thought of that as well. All they can say is “no”. I’m so perplexed by it, and obviously something isn’t right, so I suppose it’s worth a shot.
Thank you.
 

Arch Hoagland

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Jul 11, 2014
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3,734
Location
Clovis California
Contact the maker of the RV and see if they will authorise a local RV place to look at it.

I had a Thor trailer that the dealer couldn't get to for three weeks.

Thor authorised an RV repair place within two miles of me to fix it.
 

John From Detroit

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Apr 12, 2005
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24,779
Location
Davison Michigan
Even reversing the direction of the motor won't change the direction of air flow with a blower

Sounds like the cover is bass ackward. Air is sucked in the FRONT half of the unit (Front towards the front of the vehicle as it goes down the road) assuming the condenser is to the REAR (up on the roof)

On Colemans. on the Condenser air is sucked IN through the condenser. this is opposite of other makes, but the indoor air flow is the same Front to rear.
 

OldMarine

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Joined
Apr 30, 2020
Posts
60
What is reverse polarity?
reverse polarity is when positive and negative get reversed from the normal position. Not sure it's possible on a fan motor, but if it is, that could explain it running "backwards".
 

rskrbina

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Joined
Mar 2, 2014
Posts
108
I had similar issues with my Mach units. (2). I pulled down the ceiling cover and found the foam partition that is supposed to keep the return air seperate from the forced air had fallen out of position, thus mixing both return and forced air together. (Not good). I got some HVAC tape, put the foam partition back in it's place and taped it back in place. Cold air out of the vents!! All is good. You can look inside your a/c unit by taking your return air filter down as you would to clean it. Then get a flash light and take a look inside to see if the foam partition is in place or not. I hope this helps.
 

Ray-IN

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Mar 16, 2014
Posts
233
Location
North America-somewhere
I had similar issues with my Mach units. (2). I pulled down the ceiling cover and found the foam partition that is supposed to keep the return air seperate from the forced air had fallen out of position, thus mixing both return and forced air together. (Not good). I got some HVAC tape, put the foam partition back in it's place and taped it back in place. Cold air out of the vents!! All is good. You can look inside your a/c unit by taking your return air filter down as you would to clean it. Then get a flash light and take a look inside to see if the foam partition is in place or not. I hope this helps.
That's what I was thinking while reading the replies. The return air plenum is not sealed.
 
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