Not quite, there is a WOT throttle relay but all it turns off is the compressor, not the fan. You shouldn't be able to keep it at WOT long enough for the air to start coming out warm. I've seen a similar problem once before but it was on my Mother's 77 Granada. The fan would cut out whenever you put the throttle more than half way down. It turned out to be vacuum related. I seem to remember her saying they had to replace a modulator (not sure though). The fan should not cut out at full throttle. I would look for a vacuum related problem.
There are some A/C parts that are controlled by vacuum. It is possible that if you have a vaccum leak on one of these parts that as you give it more gas it is making the leak worse. I do know there is a vacuum controlled solenoid that is actuated when you put your A/C control on MAX. It activates a solenoid that closes off the radiator coolant from circulating through the A/C-Heater system. Yours sounds more like a blend door that is changing positions during WOT. I think the blend door is controlled by a cable though and not a vacuum. Whatever the problem is, it is not right.
