PeachParts Mercedes-Benz Forum - View Single Post

LUVMBDiesels · #5 12-29-2008, 09:58 AM

One thing to look out for (at least on the W126) is that the vacuum switch needs to be shimmed when it is attached to the key switch. If it is too tight to the key switch body it becomes very hard to turn the key and could prevent the key from going over to the 'start' position. I found that out when I replaced the switch on my 300SD and looked out for it when I did the 300SDL. Since your key is not springing back from the 'start' position I believe that youhave the vacuum switch on too tight. The vacuum switch is worked by a cam on the key switch. Maybe they way it is installed the vacuum switch is being kept open. It is only a reed valve