Tonight pulling into the local Mickey D's drive thru with a/c on and at an idle.....the engine stumbles, belt squeaks, then idle speed drops like it's gonna stall and the check engine light comes on...I turned the a/c off but kept the idle up with the throttle and drove it home never letting it idle. I pulled it into the drive way, I then let it idle on it's own, it did but like at 500 rpm, turned the a/c back on....and no idle increase, hum. I decided to switch the truck off to see if it would restart, it did and the engine light went off and the idle increased to normal and the a/c speed increased when I switch it on too.....what the hell. What could have caused that? The truck is a 1995 with a 2.4