johnnyringo Report post Posted September 17, 2011 Went out to work on the coach. Started the genset and then turned on the front AC. Went to start the rear and noticed that the thermostat had no display reading (temp). Checked the AC breaker, it was OK. Moved the fan mode switch from auto to on and the fan came on so the unit has AC power. Removed the Thermostat cover and removed and checked the fuse. It was OK. Replaced the fuse and the display came on. Temperature out was 89 degrees. Set the thermostat to 78 and waited. After about 15 minutes still hadn't started. Coach is a 2004 Tiffin Phaeton 40RH. The AC units are Coleman Mach's, 15000BTU. Any idea what I can try next? Share this post Link to post Share on other sites
desmo Report post Posted September 17, 2011 I'm no technician but I had a similar problem one day turned on the air conditioner and no cold air fan would run. I read on a web site that sometimes for reasons not totally understood to turn on the heat pump and let it run for a few minutes then switch to air conditioning. By golly it worked and haven't had a problem since. Good Luck Share this post Link to post Share on other sites
travlin Report post Posted April 20, 2012 Can the roof air conditioners be recharged ? Share this post Link to post Share on other sites
dickandlois Report post Posted April 21, 2012 There are relays located in the AC units that supply AC power to the units. The relays are powered by 12 volts supplied from the Climate Control panels. So it could be a simple contact issue,or the starting Cap. Then again it could be something else. If you have not worked on one,please understand that the capacitors pack a nasty amount of voltage. If you are not used to working around them, get some help. I have some pictures of the AC wiring and of the components under the cover. However, at the time I have reached my download quota. So I will see if there is a way to forward you the info. by a P.M. (private message). Rich. Share this post Link to post Share on other sites
dickandlois Report post Posted May 4, 2012 Travlin, The answer is yes. You need a service shop, say HAVC center and one with the proper materials to make an access point in the cooling loop and the rest is about the same as any home AC system. Having said that one needs to know what the problem is with the unit. Is it just a starting cap., power circuit issue, circuit breaker / relay, cooling fan, (worst being the compressor) or a thermostat problem. Should the compressor fail, just replace the unit. Rich. Share this post Link to post Share on other sites
