All - thanks in advance for any response. I say a thread similar to this, but I have a slight twist that I am trying to figure out in my Heartland Trailrunner.
I am in the process of installing one of the Airxel Circuit Boards that will allow me to connect my A/C to be thermostat controlled. My particular thermostat is a digital LUX household thermostat. Currently, my t-stat only controls my heater, and my A/C controls are located on the ceiling unit.
Current wiring to the thermostat consists of a single red and single white wire coming off of my heater. So, that is what is giving me my 12VDC (+) and my heater control.
This thermostat wire goes up the wall, past my A/C and over the the thermostat, so I am going to tap right into that wire. Here is where I am a bit confused. The new wiring says I need to connect the control board to the thermostat as follows :
A/C -> green wire-> t-stat for , I believe, high A/C fan
A/C -> gray wire to t-state, I think this is low A/C fan
A/C -> yellow wire to t-stat, this should be A/C relay
A/C -> blue wire to t-stat - this is labeled as 12 VDC(-), and then the diagram shows that there should be a 12VDC(-) connection to the t-stat.
For the most part, I am OK with the green, gray and yellow. Although, probably at first I am simply going to wire the green and only have high fan.
My question is on the blue VDC(-) wire. Since I am using a household t-stat, I don't have a VDC(-) wire running to it. However, at my heater, there is a straight connection to a 12VDC(-).
I have seen a few cases (youtube, etc), where people do a t-stat upgrade only, and simply leave the blue wire in the wall. What I don't know from those is whether the blue wire is still connecting to a VDC(-) somewhere, and this still supplying a ground to the control board.
So, my question is what to do with the blue wire? Do I simply not connect it at all, or do I try and make a straight connection from a VDC(-) to the connection on the control board. I am wondering how important it is for the control panel on the A/C to connect to this at the t-stat? I could easily connect the new control panel straight to the VDC(-) at the same connection point at the heater and bypass the t-stat.
See the image for what I am describing, and the blue line is what I am proposing.
Link to pic
T-stat wiring
