Super frustrating AC issue

[kfp673]

Hello All,

Please help if you can because I am about to light my camper on fire and push it off a cliff I'm so frustrated!

My camper came pre-wired for a second AC (direct vent). First AC is a Coleman Mach 15K so I purchased another Mach15 for the master bedroom. After 5 hours of install for me and a little help from my wife I got the job done. Toughest part was getting it up there but we got it. Installed everything exactly as directed. Moment of truth.... fan but no compressor. No matter what setting I chose I cannot get cold air. Fan turns on every time and even the heat strip I bought with it had no problem heating but no cold air. Checked the harness that plugs into the controls and even pulled apart the entire upper unit to look or a lose wire or something obvious. Nothing. Last ditch effort was to try my generators for power since my shore power at home is a standard 20A 110 outlet (though that has no problem running the other AC by itself). Tried the generators (which also run the other no problem) and same result. If this thing is dead and I have to replace the unit I think I'm going to lose my mind. Wasted all day today for nothing!!

If you have any suggestions please help. We leave next Friday for a week in SC which pushed me to do this install this week. Thanks in advance!

[kfp673]

Just as a final reply for those interested, the AC is up and running. As noted above, I ordered and entire new ceiling piece that has the selector dial and T-Stat dial in it and plan to return the one I had. Ironically, a tech support person finally called me back 2 days after I left a message and email to be called back and after I had bypassed the T-stat. I discussed what I did and he said it still could be either the selector or t-stat, so rather than only replacing the t-stat I pulled down the entire ceiling assembly and replaced with the new. All is running well now and we are good to go with 1 day to spare for our trip.

Thanks again everyone. I will drive myself to exhaustion before I give up trying to fix things, but the replies here were a big help and saved me a lot of extra time.

[kfp673]

Weldon wrote:
Good news for sure. Is it too late to consider taking the thermostat to a local ac shop and buy a thermostat that will work with your unit? Much easier than the disconect and reinstall the complete unit.

It is just a small t-stat rotary dial so I'm not sure anywhere would have it in stock that would fit this small housing. The new unit is scheduled to arrive Wednesday so I should be fine. Actually don't have to remove the entire thing. The piece that holds the flexible plenum and the electric, on/off switch, and t-stat can all stay. Simple 2 screws and you can remove the t-stat. I'll just replace the parts that I need and return the rest in the other package. If it does not show up there are plenty of ways to rig it now that I know what to do. Thanks!

[3_tons]

kfp673 wrote:
Well... I am 99% sure I have this figured out. Thanks everyone for the links and suggestions. I have multi meter tested everything I could think of and all of the suggestions on this forum but the one thing I did not do was mentioned above and that was bypass the T-Stat. I removed the yellow and white wires from the T-stat this morning and jumped them and BINGO!! we have cold air! Ironically I had left a message for the place I bought it to setup an exchange of the AC itself, but super happy it's the T-Stat. Of course the T-stat itself is not in stock anywhere including the factory. Since we are leaving for a trip Thursday I decided to just repurchase the entire ceiling assembly and have it shipped to arrive Wednesday and then I am setting up the return of the one I have. Figured this way even if the refund and return take a long time, I am temp out $200 ish. I will post 1 final time once it's replaced. Thank you all very much for your replies and help. Hopefully some day this thread will help someone else!

Many Thanks to Doug for again sharing his sage knowledge 🙂

3 tons

[dougrainer]

kfp673 wrote:
Well... I am 99% sure I have this figured out. Thanks everyone for the links and suggestions. I have multi meter tested everything I could think of and all of the suggestions on this forum but the one thing I did not do was mentioned above and that was bypass the T-Stat. I removed the yellow and white wires from the T-stat this morning and jumped them and BINGO!! we have cold air! Ironically I had left a message for the place I bought it to setup an exchange of the AC itself, but super happy it's the T-Stat. Of course the T-stat itself is not in stock anywhere including the factory. Since we are leaving for a trip Thursday I decided to just repurchase the entire ceiling assembly and have it shipped to arrive Wednesday and then I am setting up the return of the one I have. Figured this way even if the refund and return take a long time, I am temp out $200 ish. I will post 1 final time once it's replaced. Thank you all very much for your replies and help. Hopefully some day this thread will help someone else!

Rotate the tstat to cold. Then take a punch or screwdriver and hammer and smartly tap on the Tstat housing. That may make the points close to work. But still replace the lower unit. Doug

[wnjj]

If the replacement unit doesn’t arrive in time for your trip, wire up a light switch between yellow and white so you can at least turn it on manually.

[Weldon]

Good news for sure. Is it too late to consider taking the thermostat to a local ac shop and buy a thermostat that will work with your unit? Much easier than the disconect and reinstall the complete unit.

[profdant139]

Great news -- well done!!

[kfp673]

Well... I am 99% sure I have this figured out. Thanks everyone for the links and suggestions. I have multi meter tested everything I could think of and all of the suggestions on this forum but the one thing I did not do was mentioned above and that was bypass the T-Stat. I removed the yellow and white wires from the T-stat this morning and jumped them and BINGO!! we have cold air! Ironically I had left a message for the place I bought it to setup an exchange of the AC itself, but super happy it's the T-Stat. Of course the T-stat itself is not in stock anywhere including the factory. Since we are leaving for a trip Thursday I decided to just repurchase the entire ceiling assembly and have it shipped to arrive Wednesday and then I am setting up the return of the one I have. Figured this way even if the refund and return take a long time, I am temp out $200 ish. I will post 1 final time once it's replaced. Thank you all very much for your replies and help. Hopefully some day this thread will help someone else!

[dougrainer]

This flow chart should help you. Doug

https://www.airxcel.com/DesktopModules/RvProduct/Pdf/t001.2.pdf

https://www.airxcel.com/DesktopModules/RvProduct/Pdf/1976d136.pdf

Below, look at page 10. Remember-YELLOW is also NEUTRAL.

https://www.airxcel.com/DesktopModules/RvProduct/Pdf/1976141_copy.pdf

[wnjj]

kfp673 wrote:
Purple wire comes off the back of the selector knob. At the back of the selector knob it has 120v, it then runs via the harness up to the housing where the capacitors live where it is spliced to a back cable. 120V show there as well. Black cable then runs to the compressor which has 120v (actually they all ready about 117 + or -. Both sides of the capacitor also reads the same 117 ish.

T-stat has different colored wires including white. Anyone know how to properly test a rotary t-stat with a meter? The ceiling unit is model 9430D7153. I find it strange that I hear and feel no "click" when I rotate the t-stat knob. I would think I would feel that if it were working and sending a signal to the compressor to engage.

If you have 120V everywhere on the compressor you don’t have a complete circuit. Look here for a Coleman wiring diagram which likely is similar/the same as yours: https://ricardolevinsmorales.com/wp-content/uploads/2018/09/coleman-mach-air-conditioner-wiring-diag...

In that diagram the yellow wire from the thermostat should be connected to the neutral (white) wire when on. If the yellow wire is at 120v it means it is open circuit and being pulled up through the compressor coil.

I’d say you have an issue at the thermostat. If it’s like the above diagram, white should connect to yellow when calling for cooling. You should be able to manually override by connecting yellow to white.

[kfp673]

dougrainer wrote:
I still need the MODEL of the roof top unit. Doug

48204-669 Coleman Mach15

Indoor unit 9430D7153

[dougrainer]

I still need the MODEL of the roof top unit. Doug

[dougrainer]

If the purple wire has 120 volts then the power goes thru the tstat. The absence of a click does not signify much. I use a heat gun to warm up the tstat cap tube to verify if the tstat point opens and closes. Doug

[3_tons]

My pre-retirement motto was “Improvise, Adapt, and Overcome”!!….Kfp perseveres !!

3 tons