No power to the air conditioners

[Michbigmike]

I cant get my air units to power up. I have my unit plugged in to a 50 amp service and power to the breakers but nothing at the thermostats. Battery is at full charge. I do have a bad carbon monoxide sensor in the bedroom that is bad and dis-connected from the power source. All the fuses are good and all the breakers are good. Any ideas on what is wrong?

[Northofu1]

Hey Mike,
Year, make and model would help. Is your battery disconnect off?
Are you using the In Command system? Just spit balling until someone else shows up.

[chuckster57]

How do you know you have AC power coming out of the breakers? Have you flipped the breakers fully off and then back on?

[Michbigmike]

Sorry, it is a 2013 keystone fusion toy hauler 315. Both units are not working and I have no power to the thermostats. All the fuses are fine and I have full 12 volt dc and 120 volt to the unit. I have no manuals for any of the appliances but I do have a general manual on the trailer but nothing that helps me with my issue. The carbon monoxide alarm is out-dated and needs to be replaced. It was not hooked to the wiring on the trailer. I have no other issues electrical wise. I did find the furnace. Wow. Under the toiler. Who knew?

[chuckster57]

12V for the thermostats will come from the control box in the AC return duct. If you have older analog thermostats, they have a glass fuse in them.

[flybouy]

A picture of your thermostat would help. No 12vdc to the thermostat is an issue. Need to find out why first, has to be a fuse for it somewhere.

[Michbigmike]

I checked the fuses to the thermostats and I have 12 dc through the fuses. I have 120 volt to both breakers and I re-set hem several times.

[chuckster57]

I checked the fuses to the thermostats and I have 12 dc through the fuses. I have 120 volt to both breakers and I re-set hem several times.

If you have 110VAC at the AC control box and 12VDC at the thermostats then I would say either the thermostat is bad or the control box is bad.

If your not getting the signal to the control box for AC or Fan, I wonder if you can put 12V to the fan hi or lo to rule out the thermostat

[Michbigmike]

Hey,
Well I got the problem solved. I did not know that using a volt meter to test fuses is best if the fuse is re3moved from the thermostat and check polarity. Checking them while the fuse is still in the socket allows the voltage from the hot side to go through the meter and show 12 volts. Changed out the bad fuses and both units are working just fine. Don’t know why both were bad. Oh well!
Thanks for all your help.

Mike

[Gravytrain]

I cant get my air units to power up. I have my unit plugged in to a 50 amp service and power to the breakers but nothing at the thermostats. Battery is at full charge. I do have a bad carbon monoxide sensor in the bedroom that is bad and dis-connected from the power source. All the fuses are good and all the breakers are good. Any ideas on what is wrong?
Not sure if this will help, but on my 2016 Carbon 347, I had intermittent connections for the 12 VDC power to my aft (Zone 1) Air conditioner that made my thermostat inop. Apparently the 12 VDC goes to the aft air conditioner and a second wire on the same connection at the air conditioner supplies the 12 VDC to both the thermostat and the bedroom (Zone 2) air conditioner. Keystone also used solid-conductor thermostat wiring for the power and digital bus connections between the air conditioners and thermostat instead of using twisted pair wiring that is needed - this is known to cause intermittent thermostat problems with the two zone thermostat. Hope this is helpful.

[wiredgeorge]

Mike hasn't been on the forum since July when he was having the A/C issues. Note his last post was his last appearance. Good info though.

[Jarvis]

Gravytrain I’m having this same issue how did you fix this?

[hankpage]

Gravytrain I’m having this same issue how did you fix this?

Jason, You have posted to a two year old thread and this member has not been on in over a year. You will have better luck starting your own thread and giving a full description of your trailer and problem. Good luck, Hank

[sourdough]

Gravytrain I’m having this same issue how did you fix this?


That poster hasn't signed in for about 1 1/2 years.

[Gravytrain]

My problem was traced to poor crimps & broken wires near the aft A/C unit. The manufacturer used solid copper thermostat wiring (house wiring) and the conductors broke inside the insulation near the crimped on spade lugs. I also had some bad crimps for the spade connectors that plug onto the control box.
Hope this is helpful.

[Jarvis]

Thank you for your reply this is extreamly helpful