I'm trying to tackle some electrical gremlins in my 87 300e, particularly right rear window console and door switches inoperable (even though regulator/motor assembly, switches & fuse tested good), childproof rear window console switch inoperable, weak/dim trunk light, no rear dome light and no rear window defroster. The Haynes Manual schematics show the grounds, some of which are shared, and labels them as E-1, E-2, etc. Does anyone know where each numbered gound is located, or have any suggestions as to how to get this information? Thanks.

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87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

The MB 124 CD, available on Ebay for a pittance, is more detailed than the Haynes manual. The CD is a tad cumbersome but the answer is always there.

Trunk light is called W6 in manual and is in trunk -left weel well below hinge (see first attachment).

The child safety switch is W12- (part of rear window circut as are both center consol and door switches) is under center consol (second attachment).

But be sure to check the wires in the door pass-through housing for breaks that is most likley to be your problem for the rear dome and window.

Attached Thumbnails

   

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-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

Tonite I checked and Haynes labels the grounds as E-6 and E-12. I recall reading somewhere on an old post that MB put out a repair kit I think for the in-door passthrough. FYI, this weekend I took off the seatbelt trim on the right rear pillar and all the wires and connections looked good, but I will double check everything for breaks in the wires. Thanks.

I also noticed that the previous owner had wired a radar deterctor into the two leads going to the cigarette lighter. (The only other mod is the Kenwood indash head unit, which I have not pulled out so I don't know how it was connected, although the fader control still operates so it may use the original harness or wires.) Do you think that the radar detector installation could be causing my problems? There isn't much room down there and I'm reluctant to resplice the wires back to the original, but maybe I should try that if all else fails.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

Where they break is under the rubber housing that can be seen between the body of the car and the body of the door with the door open. The rubber pulls back and the isulation needs to be cut off. It is very tight but if you sit down right in front of it and go slowly with a bucket of patients, it's not so bad. Its the combiation of gettig to be 20 years old and the opening and closeing of the door that gets it there. I had the same symptoms, window and rear dome light, when those wires were the culprit.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

This weekend I'll remove the braided sheath and inspect as you suggest. Thanks again for your help, Marty.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

Well it took a few months, Marty, but you got it right-most of the wires, including the ground, were broken under the rubber between the rear door and the body. Reconnected them and the rear window finally worked, without the need to pull out the motor/regulator assembly. The rear dome light now also operates, but not correctly, and the trunk light is very weak. I replaced the trunk light switch and checked the ground in the trunk, and they aren't the problem. Also, the rear dome light only comes on if I disconnect the trunk light. I'm going the check the left rear door switches next. Any suggestions would be welcome.

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)