Where is G102 ground on 450SL?

[marinmbfan]

In my 1980 450SL, I've been putting up with a flaky cruise control for a while, and low speed on my wipers that only works when I hit a good bump, but now that both power windows quit on me, it's time to track this gremlin down. I think my problem is a bad G102 ground, because according to my factory wiring diagram, all my bad bits terminate there. Trouble is, I can't find the darn thing.

My wiring diagram says (under Component Locations) that it will be "behind instrument cluster". I pulled my steering wheel, pulled out the cluster and --- nothing. Then I saw Gilly mentioned in thread 17926 that on somebody's 500SL they'd find it to the right of the glove box after pulling the box. I pulled the glove box and -- nothing. I give up. Where is this beastie? It looks like 8 or 9 different items terminate there, so I think I'm looking for a big screw with a bunch of brown wires going to it, but so far no dice. To the right of my glove box -- waaaaay off to the right, I see a bundle of brown wires disappear into the body work. Can someone help me with a few landmarks and what it will look like when I get there? Thanks for any assistance.