Been having a wierd issue with my truck when I turn on the a/c. Trucks runs great no problems but when I turn on the a/c it puts a load on the truck and the idle goes down to like 550-650 rpms sounds like it wants to die but it doesnt. Any ideas.

 

How do you new guy,s expect us to help you when you provide no useable information ?, like what year truck you have and what engine it has ?.

 

there is an a/c idle adjustment screw. turn on the a/c and when the compressor is engaged adjust the idle. don't go over 1000rpms though.

 

The truck is a 1991 with a 22re motor 4x4 5 speed

 

your idle up valve for the ac is not working....

 

Can you tell me where the screw is so I can make an adjustment.

 

Passenger side foot well, remove the glove box and look up there. Knob on a black box with "RPM" label.