We had 4 days of monsoon-like rains last week, and I got water incursion in right rear footwell. Standing water! Sunroof drains run ok, and water on the doorsill lead me to suspect rubber problems, rather than leaking body seams as suggested by the LWB service bulletin, but I'm open to suggestion. I shop-vac-ed the water out as soon as I discovered it, followed by a de-humidifier to really dry it out, but I still have electrical troubles related to the right rear door. The power window doesn't operate, and the "door ajar" warning is always engaged, interior lights on, airbag dash light on, even after a battery change and all that. The wiring harness from the door goes into the pillar, and then must go down onto the floor, and have some connectors that got wet and corroded or shorted, right? Any other theories? Any experience in the wiring in this area, or in the removal of pillar trim and/or carpet is welcome.
I have two young granddaughters for another couple of days, and this is my only driver with a back seat for booster seats, so all I can do until next week is think about the problem.

 

You need to follow the TSB for water ingress to rear right seat. Could be from door or trunk.

You have to remove the passenger seat and pull up the carpet. There is styrofoam under the carpet that soals up that water and forms mold.

Get a shop vac and press it into the styrofoam to get the extra trapped water out.

Biggest offender is the large rubber piece behind the door. Rain water gets behind it and goes straight to the floor.

How do I know?

Personally experienced the above in two X350's - clearly a manufacturing issue.

 

Thanks. Any way to test that rubber seal? Or should discretion be the better part of valor and just replace it immediately?

 

No need to test it.

Just grab your hands on the TSB (its here on the site or send me a PM with your email, I'll shoot it over to you) get some marine grade clear silicone and have at it.

Once you take care of the areas as outlined on the TSB you'll be good to go.

 

I have the TSB, and now I understand it. Each of these fixes deal with a place where water can sneak in under the rubber seal. I assumed it was the rubber failing to do it's job. BTW, you sound as though your knowledge was hard gained and ruefully won. Do tell!
And Thanks Again!

 

I finally finished my rear carpet removal so I can get on with finding/fixing the water-in-rear-footwell syndrome. I thought the problem was only on the right side, but I can now see that the left side was also wet. I went through a quick and heavy rainstorm, had a bit of water in both footwells, but no time to get out my Sherlock Holmes outfit on to see if I can find the actual source of the ingress. I'd like to know the answer before I slather all the suspect places pointed out in the TSB.
By the way, my 75 mile trip to Indianapolis and back showed an amazing fact I had never noticed before: the automobile is a tin can on hard rubber tires until the carpets go in. I was surprised by the thickness of the foam pad under the carpet when I took it out to clean and dry, but the sound in the car without it is astonishing. I now see why the hot rod programs on Dish Network show a step of Dynamat installation when finishing the interior of the nicer builds. It's expensive, but I can see (and hear) why it's done.

 

Hello Pete,
How do you remove the rear carpet, please?
I am trying to find the Ground Point for the Air Suspension Module?
Regards,
Ray

 

Remove both driver and passenger seat. Remove from car for better access. Remove bottom of rear seat.

Remove plastic bottoms between carpet and door.

 

Thanks Abonano.
Do you mean the grey plastic 'flashing' which is trapped under the stainless door plate and covers the edge of the carpet? If so, do I just try to prise it up, please? Abonano, I'm trying to find Ground Point G17 (from Don shown below) and I don't know whether I need to disturb the carpet to find it? The only wiring I have found in that area is shown under Don's diagram.

 

Yes, just pry up. Be careful with plastics as the tabs break easily...

G17 is under both the carpet and padding. I believe in the area right under where the seat bolts. Usually, it should be dry even with the water ingress issue. Should be very clean...

 

Thank you Abonano, got the flashing up okay...