Same here. went to napa and bought a 134r kit and followed the directions. if your system is MT, the pressure sensor will not allow the clutch to engage. once it sees psi, it will click on. FYI, get a kit with the longest hose available since the ports are a little hard to get to. cant remember the brand i used "AC Pro??. mine works just like the glossy Mitsubishi brochure.

1991 LWB Montero LS 213kmi - original. Stock.
2003 LWB Montero LTD 95kmi - original. All leather, stock and sweet

----Drive it like you have to use it to get to work in the morning.----