Hi Marty, I'll be at our RV in a few days and I'll try the various settings and let you know. Bruce

Thanks for your input. On my unit you can scroll through all settings. Auto, high and low with no appreciable change. You can tell when the compressor kicks in there is a very slight change in speed. Can you determine a difference between your high and low speed fan? On mine there is no difference. That is why I think I have my low speed fan out. There is two fans in my two A/C units low and high. I have found some documentation from Coleman Mack that trouble shoots low and high fan problems. I would not have a problem with this except for the noise associated with running the A/C on high all the time. Appreciate any input you may have. Thx Marty