wvujazzman Report post Posted August 15, 2018 OK, Folks... looking for some thoughts on where to start with this one. The dash AC in my 2003 Dutch Star apparently has two settings: North Pole and Equator. If I turn it on and have the temp dial the whole way to the coldest setting, it works VERY well... but if I move it no more than 1/2 inch or so, within about 3 mins I'll have warm air blowing out of the vents. There appears to be no in-between. I know it's not the compressor because I do get cold air. I'm wondering if it's possibly a controller issue and I need to replace that dash controller... or maybe there's a board somewhere I'm not aware of? Any assistance would be greatly appreciated! Thanks, Eric Share this post Link to post Share on other sites
desertdeals69 Report post Posted August 16, 2018 Make sure the heater valve is shutting off all the way. Share this post Link to post Share on other sites
dickandlois Report post Posted August 16, 2018 wvujassman, Welcome to the forum ! The best guess is you coach is equipped with this system. uses DC power and Vacuum to control the cold and hot mixture and where it is directed to - floor - vent - defrost. You need to cycle the system from A/C to Vent and Defrost to check the Vacuum system. Then you posted that it is ether to cold or to hot when you turn the temperature knob. This is part of the wiring that controls the mixture. Air mix servo pdf. This is the complete wiring diagram for the system I think is in your coach. Denso_RV_HVAC There is a test fixture that is used test the DC servo mixture motor system. This is the best way to pin down the problem. You might contact The REV Group for some possible service locations. The repair of these systems is well beyond most skill sets of the coach owners - so you might want to contact the REV https://www.revgroup.com/rev-group-best-luxury-rv-manufacturers Rich. Air Mixture servo.pdf DENSO_RV_HVAC_Wiring_Diagram-Electronic_Dial.pdf Share this post Link to post Share on other sites