1998 240sx se no ac after recharge

[s14280zx]

My origional low pressure hose (the one that runs along the engine to the firewal) had a visible leak and leaked all the freon out, so after running it for a year without ac, I ordered a new hose from the nissan dealer($158.00, OUCH) (95's and 96's do not work on '98's). I recharged the system, but it doesn't kick on and blows warm air. I was told by a former nissan mechanic that the compressor has a safety switch that trips when the freon gets too low, and somehow you have to jump wires to activate the compressor again. If this is the case, how do I do this, and is there any other thing I should check? THANKS

[s14280zx]

I thought it might be low on freon, but my gauge on the recharger said it was full. The compressor kicks on when the ac button is pressed, and the engine speeds up slightly like it always did, but it still blows warm air. I switched the blue relay with the one for the low speed fan control, which are both the same, but both the compressor and the fan work. Is there a switch that needs jumpered that will activate the compressor, or something I should look for? Any help would be appreciated.

[s14280zx]

I added another can of freon today since I only put 12 oz. in. It took atleast an hour for the car to take it, and it still blows warm air. Does anyone know what I should do, or check? Please help.