ashutt

I am installing a shift light this week. However, I can't determine where to enter the cabin of the car from the engine bay. Anyone have any experience with this? Basically, from under the hood I don't see anywhere where wires enter the cabin from the engine bay.

I suppose I could run under the car and drill a hole up into the floor area if needed but would rather not go that direction. Thanks for any help in advance.

mbenzman

I would run any wires in from the engine compartment in through the fuse box. There is usually extra weather boots there you can pierce to keep a good seal. It will open up to the interior to the rear and below the fuse panel. You will also have the power to pickup from there as well.

ashutt

mbenzman,

There are two sections of the fuse box. Do I have to remove the entire fuse box or just open the front or rear portion of the fuse box?

The first portion, which is closest to the front of the car, opens and has the fuses on the top but appears to have space below those fues that I have not examined because there are several screws to remove. The second portion, which is closer to the dash I have not opened yet. Can I just open this portion?

Any further advise would be greatly appreciated.

Also, you wouldn't know how to identify the negative wire on one of the 8 coils would you?

mbenzman

You would take off the entire cover removing the screws around the perimeter. then loosen the front fuse panel and pull it up to give yourself room. You can lift the relay panel if needed as well. Be careful not to set the panels down on a grounded surface and accidently fry something.
Raising these will allow you to pass wires through to the cabin through the rear part which opens to the interior above the left lower instrument panel cover.
As far as your coil question goes, heres some general Mercedes wiring code info. A ground is a brown wire. A switched ground will be brown with another color added. So I would say the brown with a colored striped wire. But I'll check for sure tomorrow for you, as I'm home right now.
Why do you need a shift light?

ashutt

Well, after looking in the engine bay, I found the spot to run wires directly into the cabin. It turns out there is a round black rubber plug to the left and down from the drivers side fuse box. Just pull it out and that is it.

From the cabin, you must remove 4 or 5 screws that hold up the footwell top panel but that is easy. Once you pull the panel down you will see the hole into the engine bay where the rubber plug was removed. The hole is about 1" wide so there is plenty of room to run wires or hoses as needed.

You could also go through the bottom of the fuse box as described by mbenzman above but there is no need to do so as it requires removing the fuses. This would take to much time.

Hope this helps others if they also need to do so.