Gage77, As Carl said, DO NOT leave that cotter clip in the plug. Just have it connected to hear the Compressor clutch spin & remove it. Thx. Carl,.. - Georgedont be tempted to leave the clip in to get your ac working as it will kill your compressor as it gets its lubrication from oil in the freon stream. low on freon is also low on oil. if you do add fron yourself get the one with oil in it also or a can of oil charge in addition. usually it is either a oring leak or the old hose manifold leaking where the hoses are crimped on. look for dirt caked on any ac system joint.or any wet oily connection,look for wet spots on your condensor.you may have got some damage from road debris over the winter.yours will have the r4 compressor look for wetness around the compressor shell.