I know I have seen a few post on this but I can't find it.......I know when you turn the ac on the idle is suppose to go up...well mine goes down....cools fine just want idle to go up.....how do you do this? Idle is 700 and when I turn on AC it goes down to 400......Where exactly is the idle up screw.....thanks

 

It is the brass-colored screw in the front of the throttle body (faces you when you are standing at the front of your engine)

 

That is the Idle up screw for the AC? Hmmm

 

Idle up screw for the AC? Didn't know there was such a thing. The engine rpm idle adjustment is what I described above.

 

if it ain't broke, don't fix it.

 

It may just need a good tune up.

I don't suggest you ever need to change the idle screw.
If the idle has changed it is for a reason...so look for the reason why and fix it.

 

The truck idles fine..and it had a tune up...it only drops idle when I turn on AC....I thought there was an "AC" idle up screw for the ac to raise the idle when AC is on...most cars the idle goes up when AC is applied...Please correct me if I am wrong...I just don't think it is normal to idle at 400 when AC is running....idles at 750 when not running.