I own a 1994 e320 with 155k miles. This summer my a/c would run fine except at times when i would start my car , my a/c compressor clutch would not always kick in. But i could always shut the vehicle off then back on, then turn the a/c compressor on again and it was fine. I should have worked on this problem then and not ignored it(busy me). Now i have to start the car quite a bit of times even drive the the car before i can get compressor clutch to kick in. Today i got it to kick on and i went ahead and charged refigerant because it was a tad low, but still cold. Can it be my a/c compressor relay? if you have any ideas they will be greatly appreciated . thanx