Air Conditioning problem
1998 Chevy Cheyenne 6 cyl Two Wheel Drive Automatic 197000 miles
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My A/C in my pickup only works when my truck reaches over 3000 rpms and cools fine once it kicks in. If I start to cruise at 65-72 mpg, it pretty much stays cold, however if I drop or go over this speed, it starts to warm up again and I have to gun it to get the rpms up again so it can start cooling again. What could it be? The A/C compressor was replaced 2 summers ago and worked fine the 1st season, last summer it started to act up but it was the end of the summer so I didn't worry too much, but now its getting hot again. Any help would be greatly appreciated. Thanks