Dash A/C blows out of defrost when climbing or head wind

dougrainer wrote:
The Pumps ALL make the noise, even Diesel motorhomes. It IS that inherent vacumm leak present in the system that causes the motor to cycle. You can insulate the mount with rubber or foam to minimize the noise. Doug

yes. Will do that next. I mounted directly onto the metal. some rubber washers may help. So glad to have it working again. I have had this problem since it was new, and have had so many techs look at it, try to fix it, with little to no improvement. Thanks again!