Which one am I looking for? He has a lot of them. I tried just hooking a can up to it and it wouldn’t kick it on. I was also wondering how likely the pressure switch is to go bad. Also both fans do come onYou should check out DanG144's thread, it will have some good troubleshooting for the HVAC/cooling system.
On a 2003, the fans should BOTH come on LOW speed if the A/C is switched on, even if the engine isn't running (so long as the key is on).