A/C Clutch Pressure Switch

[LEEVON]

It got freaking hot today...wasn't prepared for that. Ambient outside temp here was about 88 degrees and I've gotten really soft apparently. So I swung by the parts store and got some R134a.

I don't know the history of the a/c system in my truck, just that it's all intact and the compressor was unplugged. I figured I'd take a chance, and I realize this isn't the best way to get a reliable working system. It may take a flush and new components in the future. I also have some R12 stashed just in case. So I plugged in the compressor, started the charge and the clutch wouldn't cycle. I jumped the compressor switch, it cycled and low and behold worked (for now). I could not get the clutch to cycle on it's own with the switch plugged in so I assumed the low pressure switch was bad and bought a new one.

Can I change the switch while the system is charged?

Thanks!