Why doesn't my A/C in my truck blow air when going up a hill?

Question

It works fine when it is not at a higher RPM, it has been a problem for a while. I don't really want to take it in at this point, just want to know what the problem is. Any ideas?

Answer 1

maybe like the fan, a bad connection that loses connection at a certain angle or when you go up hill something gets lodged in the fan. does it make lots of noise or sound like a turbo?

Answer 2

Oh you're all silly. The clutch on the AC compressor is disconnecting due to low vacuum. A lot of cars do this. You may have a vacuum leak, or you are talking about a very steep long grade.  

Answer 3

yes, the problem is the A/C system has sensors that read head preasure and head preasure is reduced when cold air travels through the grill cooling the condensor coils, if your engine temp is up and your speed is too slow to flow good air through the clutch turns off the a/c to allow the freon to cool off and drop the head preasure. some models even incoporate a sensor in the coolant to keep from allowing the A/C to kick on if the engine temp is high

Answer 4

your  vacuum check valve on the vacuum line going to your hvac is leaking

Answer 5

on the 1999 dakota v8 the air line rtd was miss repo and the sizw didnt fit on the side   mine did that too!!!

Answer 6

Are you saying the engine fan is not coming on, or the blower motor isn't coming on while you are going up hill?  This could lead us in more than one direction.