First, thanks for all the messages posted so far. The belt is tight, the Kilma is OK, I think it is just low on freon....On the 86' 300E, how do I locate the low pressure switch? Am I correct in that I take the two wires off and connect them to by-pass the switch and engage the compressor to accept the freon? What order do I do this operation? Start the car, by-pass the switch, fill with 134?