The trigger path for your AC is power through a vinyl-covered bullet connector in, with ground returning through the compressor chassis to the engine, and then to the battery. There's a lot more to the circuit on the powered side, but for a quick and easy defeat of the AC compressor, you can just disconnect the bullet connector, and reconnect later when you need AC.

Simple!

Randii (who leaves his connected because the dehumidification is of more value to us with our dog than the heat it costs)