I'm sure this isn't the problem and that it has already been said in this thread, but I can't not say it: Some cars turn off the A/C compressor under WOT, or maybe under heavy load conditions.
Chrysler/Plymouth/Dodge was big on this in the 80's. I don't know if their cars do this anymore. Considering a base model K car only had like 22 HP, they needed every bit of power they could scrape up when under load.
I have a VX with A/C. With it turned on, I never hear it cycle off. It's real easy to tell when it is on, quite the big draw on power. Does it cycle off under certain conditions, like only while idling? How was it cycling before the top off?
I thought I read somewhere that the base model only had a 22 HP engine... I could have been wrong. The K cars were pretty light. My family had several. My dad's company would buy him a new car almost every year because he drove ~ 80,000 miles/year for work. Starting in 1983 he was no longer able to choose a larger car like an Impala, Malibu, or Mercury Monarch. If I remember correctly his choices were Escort, Citation, Chevette, Aries K. Dad chose the K car because of 2 reasons. First of all he said it "Looked like a real car", and Chrylser threw in free goodies on the fleet vehicles. Where Ford & GM were taking stuff off the cars for the fleet package, Chrylser was throwing in a decent stereo and cruise control.
Here's the cars we had in the 80's: 79 Chevy Impala, 80 Chevy Malibu, 81 Mercury Lynx (Escort Hatchback), 78 Mercury Monarch (He wore the Lynx out in like 6 months, and they gave him the monarch to use until he qualified for a new car again.) 83 Dodge Aries K, 85 Plymouth Caravelle, 86 Plymouth Caravelle, 88 Plymouth Voyager, 88 Chrysler LeBarron, 89 Dodge Caravan, then we started driving my sisters had an 84 Aries K, and an 89 Aries K.
We had pleanty of K cars over the years... They were all nice, reliable cars except for the 84 Aries K my sister had - That blew a hole in the piston at 98,000 miles. My mom's 88 LeBarron was a good car. We had put over 200,000 miles on it before we sold it, and it was sold to a friend of my mother's son. I think he ended up with over 300,000 miles before it gave out. The only real problem with that car was the digital instrument panel would go crazy once in a while. The only way to fix it was to shift into Neutral, shut off the car, then restart it.