AC help

[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!

[chuckster57]

Silly question, did you set the thermostat knob to the coldest setting?

This ac unit has ceiling controls?

[kfp673]

Originally Posted by chuckster57

Silly question, did you set the thermostat knob to the coldest setting?

This ac unit has ceiling controls?

Yes. Direct vent with ceiling controls. Yes turned to cold and tried every other setting as well to make sure I did not install knobs wrong or whatever. Checked every connection on the roof to make sure nothing is lose. No compressor sound at all

[chuckster57]

Since the only wiring is the Romex and plugging in the roof unit, I’m wondering if a capacitor hasn’t failed.

[kfp673]

Just made my third trip to the roof for another 90 minutes. Did some research on testing capacitors. Set my meter to the highest ohm rating, discharges the cap, and then tested. Started low and worked it’s way up. Stopped testing when it got to 70 as the ramp up apparently shows it’s fine. Also set my meter to AC and tested individual leads going to compressor. They each read around 12v. I think Injust for a junk unit. I am so beyond frustrated. No way I will have time to get a new unit in time for my trip on Friday. Brand new AC run today for the first time and can’t cool!! What junk!

[sourdough]

Just brainstorming here but have you checked the control panel to make sure the thermostat knob is actually doing anything? I am assuming the fan knob is running it through the fan speeds.

[chuckster57]

All I can say is I’m sorry, I have had a lot better luck with the Coleman Mach vs the Dometic units. I would be on the phone first thing Monday morning.

[chuckster57]

Originally Posted by kfp673

Just made my third trip to the roof for another 90 minutes. Did some research on testing capacitors. Set my meter to the highest ohm rating, discharges the cap, and then tested. Started low and worked it’s way up. Stopped testing when it got to 70 as the ramp up apparently shows it’s fine. Also set my meter to AC and tested individual leads going to compressor. They each read around 12v. I think Injust for a junk unit. I am so beyond frustrated. No way I will have time to get a new unit in time for my trip on Friday. Brand new AC run today for the first time and can’t cool!! What junk!

Shouldn’t the compressor get 120VAC?

[kfp673]

Originally Posted by sourdough

Just brainstorming here but have you checked the control panel to make sure the thermostat knob is actually doing anything? I am assuming the fan knob is running it through the fan speeds.

Yes fan knob is running through the speeds. I installed the heat strip as well and that works fine. T stat has all wires connected and certainly spins but tough for me to tell if it’s actually working