Texas Toast

Handling the Texas Heat

We’re set up in Temple, Texas at Live Oak Ridge Park on Lake Belton, and daytime temperatures are reaching 90F while overnight temps are mid-70s. So it’s a bit toasty during the day.

Lake Belton is great Corp of Engineers (COE) park with no day-use access so the only traffic in the park are campers. The newer lakefront sites are 50-amp while the older sites furthest from the lake are 30-amp.

We are here for an extended time and had to move sites from a 50-amp to a 30-amp site, and just before moving it got warm inside overnight. I did some checking and found the bedroom A/C stopped working.

I did a lot of research as I am not one to call a mobile technician unless I absolutely can’t fix it. We’ve got Coleman-Mach air conditioners and the bedroom is a cool-only with no heat pump. Here is the process I used for troubleshooting:

1) At the thermostat, the fan would run when switched to ON but would not turn on with AUTO.

2) With the thermostat ON I climbed on top and found the compressor running, so that reduced the likelihood of a capacitor problem on the AC.

3) With my suspicions on the thermostat, I double checked the fuse and breaker panel to make sure all was good, and it was.

4) I found this link to troubleshooting the Coleman-Mach system, and started with checking 12vdc at the thermostat. I had 12v at the red wire but no 12v between the yellow and blue, as outlined in the troubleshooting flow chart.

5) I put a jumper wire between the red and yellow wire (which provides 12v to the compressor relay) and the AC worked. That told me the thermostat was bad - even though I could hear the “click” when the thermostat was switch to AUTO, COOL, and set below the room temp.

6) A local RV dealer about 30 minutes away has the thermostat I need in stock.