Why does my A/C blower switch from vent to defrost when I accelerate?
I have a 2001 Dodge Ram 1500 with the V6. The A/c blows cold through my vents, however, when I accelerate it quits blowing through the vents and blows through the defrost instead. I have also discovered I have a heater core issue. My heater smells like antifreeze, steams up my windshield and does not heat very well at all. Could these two be related?
At idle there is high vacuum in the intake, therefore in the vacuum system. When you accelerate, the vacuum drops and the diverter on the HVAC goes back to where it would be with a good vacuum source. Look for disconnected, cracked vacuum hoses up under dash. But I don't think the two issues are related, the odor is a leak in heater core, probably just a pin-hole but that's all it takes