It took me awhile but I'll add this lesson.
It took forever to cool my Suncruiser in the sun, often 6-7 hours after a hot day on the road. The temp drop at the vents were fine. I have the basement air Coleman mach 2-ton unit (24000 BTU.)
I learned that it's a double compressor unit, a design the allows such a large AC to run on a 30 amp supply if needed. I watched the current meter on the management center and saw the amps drawn were only enough for one of the compressors, the second never came online. This was the clue.
Using "duner"s post, I was able to reveal the connection box on the rear quarter and check all the components of the AC unit. I could cheat and jumper the relays so both compressors would run. --They did. So now I knew the AC was functioning as is should, but not in normal use.
After checking the relays, I went back to the thermostat. Turning it on to cool GREATER than 4 degrees cooler than ambient, , I watched and LISTENED. First compressor, OK, current draw around 15 amps. One minute later, I hear a faint click, the sound of the delay relay closing to start the second compressor (so the current stays under 30 A. BUT the current did not go up, the compressor did not turn on. I tapped the board, and pressed on it a little-then it came on.
So-replaced the thermostat, all is now as it should be. I went with the factory model though a newer unit. that required a simple wire mod.
I was only getting half my AC cooling all this time. Fixed.
file:///C:/Users/King%20Martin/Desktop/Document%20vault/Basement%20A-C%20Removal%20Procedure-Revised%208-24-2013.pdf
Coleman Mach - Two Ton HE Combination Heater & Cooler | Airxcel
MARTIN
Florida.
Linear Mode
