I have a 2001 Ford Ranger XLT 2.5l 4cyl. When I turn the A/C on the idle tends to drop when I am shifting out of gear into neutral. The truck doesn't do this when the A/C is not on and also doesn't do this when the vents are on. Any ideas? When I adjusted the idle position up to about 1100 with the manual idle position screw the rpm drop stopped but I'd rather fix the problem instead of running my idle high. Any ideas would be awesome, been trying to figure this out for 2 years now. Thanks.