Have a 5er with 50 amp service. AC is a 15000 Dometic 11 years old that has only been used sparingly, not full time. The last time I used it I thought it was slow to come on but it did and worked well. Past week-end tried it and nothing, no compressor, no fan no sound at all. Breaker is ok and fuses are good. Replaced the "starter" about 4 years ago. Put on a hunter thermostat about 7 years ago. The furnace would not come on as well. Still have the old thermostat so I put it back on...no air cond. But the furnace did come on, turned it off double checked wires to thermostat and furnace came bacon even though the switch was OFF. Eventually turned it off some how. I feel I have wired the old thermostat incorrectly, it is wire as Black to ground, Orange to fan, Blue to Hi fan, Yellow to cool, Red to 7.5, White to furnace, Green is not connected.I also have 13000 ac in the front which works fine, it is not on the same thermostat.I would appreciate your thoughts as to the problem and if someone can give me the correct wiring for the Dometic thermostat that came with the unit 11 years ago.Thanks for your help.

Look in the junction box in the filter area make sure the 110 wire is connected and tight

Come on guys, how about some comments.

The problem with going by colors is that the coach maker installed those colors- not Dometic, so they may not cross over, but you can look at the ceiling assembly to see what colors come out of the control box, and wire accordingly.That said- *if* the black is ground, it's correct, otherwise green should be ground.If the control box is OK, twisting all wires other than white and red together will give you high fan cool- if it does, the problem is in the thermostat, if not, the problem is wiring, control box, or power to the control box (12 volt or 120 volt).But- Dometic has had a bunch of thermostats, all of which operate differently. Knowing which thermostat would help.... a lot.

Chris, it looks like the Dometic 310699-5 analog thermostat. If the furnace came on would that indicate power is okay? Is their a way to check the control box to determine if it is good?Thanks for your help.

OK- it looks like that is an early system by the colors. You should be able to shirt black and orange to get low fan, black orange and blue for high fan, black orange blue and yellow for high cool.I put the troubleshooting guide for this here.

Air condtioner wont come on | Good Sam Community

newman_fulltime
Explorer II
Jun 01, 2015
Look in the junction box in the filter area make sure the 110 wire is connected and tight
Weldon
Explorer
Jun 02, 2015
Come on guys, how about some comments.
Chris_Bryant
Explorer II
Jun 02, 2015
The problem with going by colors is that the coach maker installed those colors- not Dometic, so they may not cross over, but you can look at the ceiling assembly to see what colors come out of the control box, and wire accordingly.
That said- *if* the black is ground, it's correct, otherwise green should be ground.
If the control box is OK, twisting all wires other than white and red together will give you high fan cool- if it does, the problem is in the thermostat, if not, the problem is wiring, control box, or power to the control box (12 volt or 120 volt).

But- Dometic has had a bunch of thermostats, all of which operate differently. Knowing which thermostat would help.... a lot.
Weldon
Explorer
Jun 02, 2015
Chris, it looks like the Dometic 310699-5 analog thermostat. If the furnace came on would that indicate power is okay? Is their a way to check the control box to determine if it is good?
Thanks for your help.
Chris_Bryant
Explorer II
Jun 02, 2015
OK- it looks like that is an early system by the colors. You should be able to shirt black and orange to get low fan, black orange and blue for high fan, black orange blue and yellow for high cool.

I put the troubleshooting guide for this here.
sljkansas
Explorer
Jun 02, 2015
Have you checked the breaker for the Air conditioner. If it had tripped, did you turn the breaker to the off position before flipping it to the on position?
Weldon
Explorer
Jun 02, 2015
Yes the breaker was checked.
Weldon
Explorer
Jun 02, 2015
Thanks Chris for the troubleshooting guide and other information. Will be a couple of days before I can get back to the 5er and work on it. I am thinking I will buy a new thermostat being as the old one is 11 years old and the Hunter I took off is 7 years old.
We had a lot of storms in the area last week....if there is only one leg of the 50 amp plug working could that affect the AC?
Chris_Bryant
Explorer II
Jun 02, 2015
Weldon wrote:

We had a lot of storms in the area last week....if there is only one leg of the 50 amp plug working could that affect the AC?

Yes- it easily could.
Chandalen
Explorer
Jun 02, 2015
Is it the plug ( the pointy part) or the recepticle the other part. If its the plug rewire it or replace it so it works. If its the recepticle.. find out -why- one leg is out. Correct that issue.

A simple work around may be to get a 50a to 30a or 15a (standard household plug) and try the AC.
*An AC should not be ran for long on a standard 15a extension cord, however for your testing purposes it would be fine