Water gets into Wiring Harness (W126 '89 300SE)

[Michael Stoic]

I had to remove the right rear door panel for some general maintenance and to fix the window regulator, but that's not important.

What's important is that on the bottom of the door there are two wire harness extensions in a plastic housing. The two-wire section feeds the small lamp that turns on when the door is open. The three-wire section feeds the ashtray cig-lighter.

As we all know these contacts need to be removed in order to remove the door panel. I did just that and proceeded to my next step, etc. when after a while I felt a drop of water on my hand. A closer inspection revealed that water is dripping down out of the two wire (bottom lamp) harness. A bit later, the same condition turned up for the other (lighter) harness.

Both of these looms, when the door panel is installed and the contacts in place, are facing up, more or less. In other words, the funnel of the plastic sleeve around the wires is facing up. The loom enters the door about half way up its height, then swoops down to the very bottom (where it is fixed in place with a tie), and then the remaining section reaches up to the light and the lighter.

Somehow water makes its way into the harness and collects in the outer loom "basin" created by its path. There is no evidence of water splashing around the inside of the rear door. The rubber accordion between the center post and the door is fine.

Anyone seen this before? Any ideas on where the water could enter the loom?

Anyone know how the loom is positioned in the center pillar (does it run up?)

No shorts, yet...