Latest MH Mods
One thing that has always bothered me in our 1997 class A, was the Coleman roof top AC units allowing the fans to remain on when the compressor turns off upon reaching the selected cooling temperature.
After doing a little research, I ran across an article on fiber glass RV that talked about a modification to the typical RV roof AC's to allow them to turn on and off like a stick and bricks unit.
The write up was created in March 2006 by a Patrick M, a senior member of that forum, but is still valid today. BTW - Coleman has blessed this modification for use with their units since the digital thermostats have a built in delay to prevent over cycling the compressor.
The process includes replacing the manual thermostat for the furnace (in my case an Atwood thermostat) with a digital one, and installing a relay that uses 12 volt DC to switch 120 volt AC.
The original poster had a single roof top AC unit so the instructions cover only one thermostat and relay installation. However, since we have 2 roof units we added an additional thermostat in the main living area to control the front unit independent of the rear unit (which also controls the furnace)
Costs for doing this were;
2 Omron relays - $9.12
2 Hunter Thermostats $23.18
60 feet 18 gauge 3 wire thermostat wire - $18.84
8 hours of my time (had to pull wire to add the extra up front thermostat) installing and testing (and it worked first time!).
Total cost $51.14
This modification is well worth the investment. Now our 2 AC units, including the fans, will cycle on and off independently of each at a temperature set on a thermostat for each unit.
If anyone is interested in additional info please contact me.
Cheers from Central Texas.
Cheers from Central Texas
SPICoaster - 2008 Holiday Rambler Alumascape Suite 5th Wheel