Originally Posted by NC300SDL

Okay, here is what I found. I was having the same problem with the key turning but no resistance when turning to start and starter not turning over either. In part #1, the steering lock housing, there is a part that connects the cylinder to the switch. If you look at the bottom of the key cylinder there are 2 tangs that line up inside the locking mechanism. The steering wheel locking mechanism runs through the lock housing. On the other end of the locking mechanism are 2 tangs that connect to the switch, part #7. They are not as large and beefy as those on the back of the lock cylinder. Both of the tangs on my assembly are broken. Therefore, when I turn the key nothing happens. After removing entire assembly (pay attention to key positions mentioned in Diesel Giants write up, very important), I removed part #7, the switch. Basically it is contacts that open and close by a cam. The springback action is actually not a spring at all but a stiff piece of metal that "springs" back into position when released. As far as your other issues, if the cam is in the right position the contacts for dash lights and glow plugs will be closed and therefore activated. I ordered a new ignition lock housing. It comes with a new switch, although I don't believe there is anything wrong with the switch itself. I intend to use my original lock cylinder. Naturally, the lock housing is the most expensive part. Hope this helps.