Change-over valve, alternator

[greenacres2]

While changing oil and some vacuum lines on our '89 560 SEL over the weekend, I ran across the following mysteries:

1) A pigtail wire about 3-4" long plugged into the back of the alternator with a piece about 1" square dangling from it. Looked like rubber coated metal, and like it should be plugged in somewhere. What could it be, and where does it go?

2) Wanted to change voltage regulator, but the oil filter housing is in the way of the bottom screw, couldn't even fit a z-shaped phillips in there. Looks like I need to loosen belt and alternator to change the regulator. Is this right?

3) Change-over valve on right fender seems to have 3 vacuum fittings, but only 2 lines attatched. One goes to the air shut-off valve and the other to the vacuum check valve next to the throttle body. Nothing is attatched to the fitting on the bottom of the change-over valve, and nothing is laying loose nearby. Should there be something else attatched, and if so, what?

Thanks for any insight you can provide.

[greenacres2]

Any ideas?