2013 Rockwood Roo - A/C advice needed

[Vansleak]

Dear All,
We have never used the A/C on our Roo because we have never really needed it but we discovered (after warranty expired!) that it doesn't work. Its' a Coleman/Airxcel. The fan turns on if its turned on manually but the cooling/compressor doesn't start - the fan blows in warm air If you use the thermostat to control the A/C, the fan doesn't turn on at all. Thermostat works fine with the heat. Planning on some warm weather camping in the next few weeks with heat-intolerant campers so we need to get this running. If anyone has any helpful advice, that would be really appreciated - to start with, could this be a bad thermostat ?

[Iwannacamp]

Let’s start first with the stat. Can you post a pic of it?

It sounds like you don’t have it in cooling mode. Could be easy to fix

Yes the stat could be bad. Some are resettable.

[Vansleak]

Picture of thermostat attached - its a Coleman Rv Camper mach Manual Thermostat. Its an older analog stat. If I set SYSTEM to COOL and FAN to AUTO (HIGH or LOW), the fan and AC do not turn on even when thermostat is set as low as possible. This is why I think the stat might be bad - the fan (and hopefully AC) should turn on at higher than setpoint in AUTO. If SYSTEM is set to COOL and FAN is set to ON (LOW or HIGH), fan turns on but there is no cooling. If SYSTEM is FAN, then the fan turns on with no cooling, which is expected. Thermostat has worked OK for the heater in the past.
Thanks again for quick response!

[Maggot]

In my goofy mind I would shoot the bug from the stat.


Depending on how handy and comfortable(or in my case nutty) you are there is an option, you could pull the schematic of the stat wiring and use a test lead to bypass stat and test the air handler to manually fire the air handler to test it. If it fires probably bad stat.



If not comfortable you could purchase and upgrade stat or the same one and try that. Probably a 60$ deal. If it fires air handler fix, if not out 60$ and onto the next bug.



Now a bit deeper you could climb on roof and jumper the wires to test the air handler too. Just not sure how comfortable you are, pull the schematic and ensure model and all matches. This would test the air handler.



Take in account I am a nut and will try anything on my stuff and have a bit of experience with electric. Been zapped and blown stuff up but that way things go in my world. Live, learn and move on.



Take it for what is worth. And if not comfortable ignore my post. If you don't have any electrical experience and are not comfortable do not attempt!!!!!!!



Also this may not be what others would do this is just how I would approach it if it was my rig. Comments welcome but please no flame.

[rockfordroo]

I replaced the Coleman-Mach T-stat in my Mini Lite with a digital Honeywell RTH111b, BUT you can buy a DIGITAL Coleman-Mach that is a plug-and-play replacement for the analog version (https://www.amazon.com/d/Programmabl...tat/B01M8LFHT3). In the long run, you'd be ahead with the digital, even if the analog is NOT bad.

In any case, I've attached the wiring diagram for my CM to Honeywell swap. Your T-stat is basically a fancy switch that connects the red +12VDC wire to the other wires as needed.

If you study the pic, you'll see that if you pull your CM T-stat and use a small piece of wire or a paperclip as a jumper, you should get the following:

• Red (R) to Yellow (Y) - AC compressor should start (don't do this too long without the fan running)
• Red (R) to Grey (GL) - AC fan should run in low speed
• Red (R) to Green (GW) - AC fan should run in hi speed

You don't need to disconnect any wiring to do this.

If the AC compressor starts, you have a bad T-stat; if it doesn't then you have an AC problem.

[ronheater70]

Have know help for this problem. But really why I love this Forum..So much knowledge on here. Hope you get it figured out!

[nayther]

Originally Posted by Maggot

In my goofy mind I would shoot the bug from the stat.


Depending on how handy and comfortable(or in my case nutty) you are there is an option, you could pull the schematic of the stat wiring and use a test lead to bypass stat and test the air handler to manually fire the air handler to test it. If it fires probably bad stat.



If not comfortable you could purchase and upgrade stat or the same one and try that. Probably a 60$ deal. If it fires air handler fix, if not out 60$ and onto the next bug.



Now a bit deeper you could climb on roof and jumper the wires to test the air handler too. Just not sure how comfortable you are, pull the schematic and ensure model and all matches. This would test the air handler.



Take in account I am a nut and will try anything on my stuff and have a bit of experience with electric. Been zapped and blown stuff up but that way things go in my world. Live, learn and move on.



Take it for what is worth. And if not comfortable ignore my post. If you don't have any electrical experience and are not comfortable do not attempt!!!!!!!



Also this may not be what others would do this is just how I would approach it if it was my rig. Comments welcome but please no flame.

This is the proper method of diagnosing the problem, eliminate the t'stat by jumping across from hot to cooling, if it runs, bad t'stat, if not something else. Did you try cycling incoming power? If it's off on an overload that may reset it; doubtful but worth a try.

[Vansleak]

Thanks all, I decided that trying a replacement thermostat was a good place to start. If that doesn't work, I'll go up top and see if I can find a bad connection or something obvious. I do think the stat might be bad given that the fan does not turn on when in COOL and AUTO but we'll see.

[Vansleak]

Yes, I did try cycling power, and checked the breaker and fuse. Everything seems to be OK on that front, especially given that the fan runs. Wondering if there might be a fuse in the A/C unit itself ?


Rockfordroo, that is also fantastic advice. Will try tonight while I wait for the new one.

[Iwannacamp]

Before you remove the stat....
pull off the front cover by pulling from the bottom up. You should see a magnetic micro switch in there. You should be able to see it close as you lower the temp.

I have the same stat on my 17’. I will look at it when I get home. I have never been curious enough to take the cover off, but I will when I get home and report back.

It’s hard to beat a mechanical stat for reliability....accuracy is another story.

FWIW if I replace mine it will be a digital with full functions....I just prefer it that way.

[rockfordroo]

Originally Posted by Iwannacamp

Before you remove the stat....
pull off the front cover by pulling from the bottom up. You should see a magnetic micro switch in there. You should be able to see it close as you lower the temp.

I have the same stat on my 17’. I will look at it when I get home. I have never been curious enough to take the cover off, but I will when I get home and report back.

It’s hard to beat a mechanical stat for reliability....accuracy is another story.

FWIW if I replace mine it will be a digital with full functions....I just prefer it that way.

You might think so, but I replaced the Suburban one in my Roo because it would only start the furnace once. Wouldn't do it again unless you turned it off and then back on. And then - only once again. Never could figure out why, but I'd say that's not too reliable. The Honeywell I replaced it with worked flawlessly for the next 3 years. And the Honeywell in my Mini Lite has worked flawlessly for 4 years.

[Iwannacamp]

Well poo. It ain’t mechanical at all except the switches. Here is a manual(I think) so you can jump to test.
Red + yellow = a/c compressor
Red + green = hi fan
Red + yellow + green = hi cool

IF you want to mess with it. It is possible with the cover on the cool selector is going over far enough to connect circuit.

Here is the manual

http://www.cleggind.com/postal_tech/...376%5B1%5D.pdf

[Vansleak]

Connected red to yellow - AC started up for the first time! Then blew garage 15A breaker! Really happy with this - will update when I put new stat in. Can't thank you all enough!

[rockfordroo]

Originally Posted by Iwannacamp

Well poo. It ain’t mechanical at all except the switches. Here is a manual(I think) so you can jump to test.
Red + yellow = a/c compressor
Red + green = hi fan
Red + yellow + green = hi cool

IF you want to mess with it. It is possible with the cover on the cool selector is going over far enough to connect circuit.

Here is the manual

http://www.cleggind.com/postal_tech/...376%5B1%5D.pdfAttachment 208330Attachment 208331

Seems to be an echo in here!

[Iwannacamp]

Unless this has already been mentioned....

There are several reasons it could have tripped the breaker. It’s hard to jump with power on and not short cycle...ie possible breaker trip. Weak compressor...hope not. Low voltage....possible.
If it does it again I would add one of these...



They are available all over the place.

[Vansleak]

Just realized - forgot to turn electric water heater off. AC + water heater = tripped house breaker.

[Vansleak]

Replaced the stat - we have AC for the first time in 6 years! Thanks all for constructive advice - your help is really appreciated.

[rockfordroo]

Thanks for getting back to us. Ready for summer now!

[bikendan]

Originally Posted by Vansleak

Replaced the stat - we have AC for the first time in 6 years! Thanks all for constructive advice - your help is really appreciated.

You need to be on here more often, so you don't have to wait 6 years to get something fixed!🤣

[Maggot]

Good job.



Still a good time to check your roof and other seals.


Maggot