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Discussion Starter #1
Hi all

Over the past few weeks, I have had a constant dead battery and thus charge the battery overnight on a trickle charger, but this past weekend did not make any difference at all.

I called the AA out (UK - Automobile Association breakdown cover) and they said the battery is being drained constantly and so the guy checked some fuses for me and measured the battery drainage at the same as removing some fuses, to see what could be causing the drain.

This is where we found under my rear right passenger seat flooded with 1-2 inches of water where all the fuses box and other compenents sit. The guy sucked up all the water and then we started the car which was all fine.

I believe this water problem is from the issue I had just over 3 years ago in which the usual rain collection reservior located under the bonnet, overflowed due to the drainage plug being blocked. The front of the car was flooded and caused my SRS light to come on. A valet and a Service Station visit to reset the SRS light seemed to solve all.

Since the weekend, now my rear registration plate lights are misbehaving. The right of the 2 lights stays on permanently and I mean all the time, even when the car is switched off. The left one does not light unless you remove the bulb from the right.

If I switch the cars lights on (normal beam etc), the registration lights behave normal and both stay lit but return to their weird state when I turn the car lights off.

The fuse chart shows the registration lights are an Electric Fuse and I just wanted to know where this electric fuse is so I can remove it and clean/replace it? I read many posts on here talking about flooding and lights not working, but nothing specific to my registration lights problem. Could the components simply dry out and return to normal operation? Is it worth changing the 2 small bulbs in the registration plate lights housings?

This is my post on mbworld.org (S500 rear registration plate lights - MBWorld.org Forums)

Sorry if this thread is not too clear but I am finding it difficult to explain my thoughts clearly on the forums and the fact that my car is poorly, frustrates me...

Thanks all

Kevin
 

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Discussion Starter #2

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Just to update thread.

Well I took a good look at the car this past weekend (Saturday's weather was dry for the morning!!).

I looked at what would be obvious causes for my water ingress into the rear seat area. I first looked under the bonnet (raised into service level height) to follow what happens to the water from the windsheild and bonnet etc when going through the grated area at the top of the bonnet.

It all collects into a large plastic dish which spans across the grated area to catch the water. If the car is flat or leaning towards the passenger side (UK) then all water will flow into the large reservoir tank with the problematic rubber drain plug thing at the bottom. (Mine was blocked 3 years ago and flooded the front of the car which seems to be common). This was clear and has been since.

I then tested what would happen if the car is parked so that it leans the other way (drivers side - UK) and found that the large reservoir tank becomes redundant and the water goes towards the other side of the large plastic dish area. The design has a small rubber outlet to stop overfilling of this large plastic dish item, but with the car parked leaning towards the drivers side, this too becomes redundant.

I removed this large plastic dish item to get a better look.

Then it hit me, the drivers corner within the engine (UK driver side) is where all of this water will be directed and so upon looking closely with a torch, this area was choc full of leaves and mush (broken down leaves/dirt & sludge), and created a kind of small reservoir itself.

"This can't be good and must be the problem" I thought to myself. I vacuumed as much as I could and scraped out the crap which a long screwdriver, paper towelling, fingers etc and then vacuumed again. This area has the windscreen washer pipes running from the engine area to the washers themselves and so had to pull the pipes away slightly to get to this area.

I then retested and no more water collecting. It now runs straight out of the front drivers (UK) wheel arch area through a drain hole and some also came out of the rear drivers (UK) wheel arch area through a drain hole, so hopefully this is it.

I checked the rear seat area with all electronics and no water came through

I checked again yesterday and all good bar a small amount of water trickle which seems to be coming from the wiring tunnel from the front of the car to the rear (i.e. where the water is getting into the rear seat area from) which I am hoping is merely the water left from within this tunnel from before my fix and not fresh.

I am now planning to use a mains powered dehumidifier inside the car to draw off the remaining water/moisture as the weather sucks in the UK about now until April. Can someone recommend do I close all windows when this dehumidifer is on, what percentage setting should I use and I guess I will know when it has done it's job as no more water will collect?

Sorry if the above goes on a bit, but I am thrilled that I (hopefully) have found the culprit for my very frustrating water ingress problem.

p.s. It rained all day yesterday and was parked in the position that caused the water problem beforehand and all was good (apart from the small trickle which hopefully is what I said above).
 

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Thank you for your detailed post - it adds more to the "water in the passenger compartment" discussion. Rather than only using a dehumidifier, you may want to raise your carpets and dry under them manually (towels or a shop vac) - then use the dehumidifier.

You may also need to remove the rear SAM under the back seat, and gently dry it with a hair dryer, per the very helpful link in your post #2 above.
 

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Discussion Starter #5
Noted regarding carpets, thank you I shall do this. Can you confirm are they just held in place by clips or the like, as I tried to move them around the rear seat/transmission tunnel, but they were very secure indeed.

I have already removed all the components under the rear passenger seat including the SAM as per my link in post #2, that was me on the other forum with photos of the bits in question. Incidently could anyone identify all the parts in the photos?

Even better, a colleague at work has such a dehumidifer that I can borrow, but too heavy to bring into work. Damm how big and heavy is it?

Thanks
 
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