Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 11-09-2003, 07:16 PM
Registered User
Join Date: May 1999
Location: Pensacola, FL USA
Posts: 48
Problem with rear dome light switch 420SEL

On the dash of my 420 SEL, W126, yr.1986, there is a rear dome light switch, which normally turns on the rear dome light and both rear door lights. Problem is, it doesn't do that anymore. It now only turns on the right rear door light.

You'd immediately conclude that the lamps in the rear dome and left rear door lights need replacing. Not so, however, because
when I open the left rear door, all of the interior lights in the rear come they should.

Then another puzzle arises, because when opening the right rear door, the only light working is the right rear door light.

In reviewing the wiring diagram, I keep thinking there's some problem within the rear dome light switch, on the dash, spite of the fact that the switch will turn on the right rear door light, while not turning on the other lights. The down-side leg of this switch attaches to the right rear door light switch and makes me wonder if somehow it's not picking up the necessary ground for the dome light and left rear door light.

I've tried to remove the dash mounted switch (000-820-59-10) but whereas it fits into a base socket, with two pens, it has a small black wire that's hard wired, which isn't shown on the wiring diagram and I can't discover from whence it comes.

I've searched the "Shop Forum" archives for three days but can't find a similiar problem. It could be that I just have a broken ground wire someplace.

Suggestions would be appreciated.
Thanks, William
Reply With Quote
Old 11-09-2003, 07:26 PM
Gilly's Avatar
Registered User
Join Date: Mar 2001
Location: Evansville WI
Posts: 9,616
The "black wire" is a fiber optics cable that illuminates the switch.

Sounds like a broken ground wire problem to me too, possibly in the area of a rear door hinge, inside the rubber conduit.

Reply With Quote
Old 11-10-2003, 03:46 AM
Registered User
Join Date: May 1999
Location: Pensacola, FL USA
Posts: 48

I would greatly appreciate knowing how to gain access to the rubber conduit at the door hinge. Can I gently pry it loose from the door, from the outside, or do I need to remove the door panel and go at it from the inside? Please advise. I don't want to risk tearing up one thing while trying to fix another.

Focusing on your idea, as to the location of a possible broken wire, I discovered that when I open the left rear door, the interior lights will not come on until the door is almost near the end of its travel. This is well past the point of clearing the door switch when the lights would normally already have switched on.

I'm guessing there's a break in a wire within its insulation, at the stress point where you suggested, which is making contact when the door is almost fully open and then breaking contact when the door is fully closed.

Many thanks for your helpful suggestion!

Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 06:16 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page