Okie-1

Ok- I've searched and really didn't find much helpful info. I need to go through the firewall with one small wire on my 2009 E Class. I looked around the brake booster and thought I seen one small grommet to the upper left of the booster that I can barely touch with my finger. Where do you guys go through????

Okie-1

Well, I got it. If anyone finds this thread via search, this is what I can tell you for the 2009 E 350. Once you remove the driver's side plastic cover above the fender towards the firewall under the hood, you will find the fuse box. Remove the cover to the fuse box so you can see towards the back on the firewall. I used a flashlight to make seeing easier. I found a grommet with nothing going through towards the left behind the fusebox. You can only get one hand in there but it is all you need. Squeeze the grommet and pull outwards being careful not to drop the thing. Once it was out, I pushed a long wide white zip tie down the hole and found it dangling once I looked up under the dash. You will have to remove the under dash cover to get to it - it is held on by a couple of screws and a white plastic screw thing - not hard to do. I simply taped the wire to the end of the zip tie and pulled it all through. Hope this helps someone out there...

pinebaron

That is useful to know.