Does anyone have any ideas on why my truck drops idle and almost dies everytime my ax kicks on and it does it very often when sitting still at idle

 

It's a 90 f150 with 351 auto 4x4

 

Take your time, think about the symptoms you are having, and elaborate on that. And throw a couple periods and capitals in there this time.

 

Ok, so I start my truck in the morning to warn up, turn the defrost on, and everytime it kicks the ac on, the idle goes way down, almost to a stall. And when I drive the truck with the ac or defrost on it does the same thing you can feel it bog down for a sec it seems like something electrical, but I don't have a clue about electrical, except the basics.

 

Is the idle fine with the a/c off? If yes I would suspect the computer isn't getting the signal that the a/c is on and isn't kicking the idle up.

 

If it is getting the signal, which tells the ecu to raise the idle to compensating for the A/C , it could be a worn compressor putting too much drag on the engine. But check the idle compensator first.

 

I was going to suggest the same....compressor pulling hard. Take the belt off and try to turn the center of the clutch with yer hand. It should turn relatively easy.

 

Good idea. I didn't even think of that.

 

Yes the idle is good with the ax off. I will tryvto turn the compressor next time I get a chance to work on it. Thanks to you both il leave an update when I get a chance to work on it.