Ok so I had pretty much my ENTIRE a/c system components replaced in 2012 (compressor, condenser, drier, radiator, expansion valves, Evap cores thoroughly cleaned). The a/c system was recharged with r-134 and blew ice cold for months. Then after the summer was over it started blowing warm air and the rear wasn't working. In 2013, found out that the magnet valve (the one part i didn't replace because i didn't know about it at the time) was leaking but when it was cold in the front, the rear was still warm. Put it on ramps at a friends house and saw the neon green fluid around the magnet valve's connections. We checked the voltage to the valve thinking pressure was causing it to leak and it's getting 9v from the van but wouldn't open. We then hooked it straight up to the 12v battery and instantly it popped open and had cold air in the rear so that was solved. Replaced o rings with the correct toyota ones and they had more grab when installing, whereas the old o rings (which I thought were new when they installed all the components) barely gripped the inside of the valve. That may be one reason for the leak but the real question is that because the area around the valve and wires going into the valve was rusted, would this cause the magnet not to open with 9v? How many volts should it take to open the valve? Thinking of just buying a new one due to my gut feeling that the rust is causing the valve to stay closed, 9v not enough to break past the rust. Lemme know what you guys think. Thanks in advance.