Thermostat wiring

[camp-n-nut]

I installed a Coleman Mach 8 15,000 btu ac with a Coleman digital thermostat The ac connection has 5 lugs (wires) but the thermostat has 6 wires. Where does the red wire from the thermostat connect to?

[Bama Rambler]

The red wire is 12v+, so it goes to a battery positive.

[camp-n-nut]

I connected it to a 12 v positive and the thermostat would not power on and all 5 wires showed that they had current.

[Bama Rambler]

All five wires shouldn't have positive voltage at the same time.

In heat mode - you should have positive power on the red and white wires.
In cool mode, lo fan - you should have power on the red, yellow, and gray wires.
In cool mode, hi fan - you should have power on the red, yellow, and green wires.

Depending on the meter you're using to test with, you could read some back feed.

[Scrapper]

Did you happen to go to the Coleman support site and download the operation and service manuals? There should be a model number on the thermostat to help narrow down the ones you need. https://www.airxcel.com/coleman-mach...cument-library

[Scrapper]

Check page #4 for the wiring diagram, pages #12 thru #15 for troubleshooting flowcharts in the following service manual.

[camp-n-nut]

Thanks for your help. I have a service technician coming out to look at it.