Loss of Power in rear after removing front ac. Momentum 350G

[weimar1032]

I have a momentum 350G. I had to remove the front ac unit as it was damaged and not working. After removing it and capping all wires etc I turned on the main power breaker. Now the ac controller in the kitchen and garage don’t turn on and the fan in the 1/2 bath in the garage is not getting power. What do I need to reconnect to establish the loop so power will work again in the ac system. Rest of power in unit is normal.

[Country Campers]

weimar1032

Do you have one thermostat or one for each ac?

I will guess that you need to attach some of the thermostat wires but do not know which ones.

Brian

[howson]

weimar1032 -- from the description it's 12vDC that's missing. Did you take pictures of the wiring during the disassembly process that you can post here? What brand of AC unit?

[weimar1032]

Country Campers there is one thermostat for each unit. So ac is controlled individually by all 3 but the Heating system in controlled by t he center one in the kitchen.

[Jlawles2]

You may have dislodged a common 12V positive or negative between the systems. This has happened to others causing various items to stop working.

[weimar1032]

howson no I did not take photos as I took it apart. But I did get a few photos not sure if these will help

[howson]

howson no I did not take photos as I took it apart. But I did get a few photos not sure if these will help

Nope--those pics don't help. What brand of AC did you remove and what is the make/model of the thermostat?

Also--forgive my tardy responses. On the road so my activity here is sparse. Provide more detail, though, and Joseph ( Jlawles2 ) or a number of other individuals can help you by looking at the AC unit's manual. Need to know what it is, first!

[weimar1032]

document-library?docId=6729.pdf howson ac are Coleman Mach air 3 correction 15,000. Model 48259-969
Thermostats are airxcel

[howson]

howson ac are Coleman Mach air 3 13,500btu. Thermostats are airxcel

A/C systems have three components: the rooftop unit (what you see on the roof), the thermostat, and a component not immediately evident that's called the ceiling plenum or ceiling assembly. Each component has it's own model number and installation manual. Can be very confusing when researching on Airxcel's website. There's a lot of different models.

To understand the wiring the individual models must be known. For example, on my 315RLTS the thermostat is a 9430 338 (shown below) The wiring for my thermostat is also shown below as a reference. The purpose is so you'll research the exact model in your camper and find the specific wiring diagram for your thermostat.

Once the exact model of thermostat and the wiring diagram is known it should (hopefully) be easy to track down where the 12v is missing.

It might be as simple as a fuse in the main Power Distribution Panel--have you checked them all? When I moved my thermostat power was removed from it by pulling a specific fuse (the fuse that powered my thermostat is shown below).. Yours may be different. Make sure and remove 12v power from your camper (all sources) before checking fuses--you don't want to compound the current problem by zapping yourself. (If you're unsure how to work on electrical circuits--time to call for a professional.)

In my thermostat there's a 2A fuse under the cover (the back pops off). That's another item to check.

The reason I'm focusing on 12v and the thermostat is because as I read through a generic Airxcel installation manual, the thermostat is directly wired to 12v power. In other words, the thermostat should show a display (and cycle through the individual selections) regardless of whether other components are installed or not. This is easy for anyone reading this to verify--remove shore power from the camper (at the pedestal or main breaker in the camper). The thermostat will still have power and all the display options (but the air conditioner will not work).

Hope this helps your troubleshooting.

Howard