Water in from SAM box

[dangermose240]

I don't know if anyone can help I've had a problem with my w203 C240 52reg for a few months it started with damp in the front SAM causing various problems. I have stripped the SAM and ECU out and have got a new unit but I need to work out how the water is getting into the box.

Has anyone seen this problem before? The seal around the box lid is just a foam one doesn't seem very water tight. I'm guessing one of the screen drains is blocked and sending water where it shouldn't be and from there its working it way into the box. It could be coming in here or where it breaches the bulkhead.

Any help would be much appreciated.

Thanks

Chris

 

[television]

There are a few seams in the wheel arches where Mercedes forgot to seal them, I do have some details on this one that you can have.

 

[LostKiwi]

This is a VERY common issue on the Smart Roadsters....
The seal on the lid is really the last resort and to a certain extent just to protect the circuit boards from physical damage as water will get in through the connection ports if its anywhere about (on the Smarts it runs along the wiring looms and in through the connectors).
The only way to sort this permanently is to find the source of water ingress and cure it.
You can protect the circuit boards from damage by using a conformal coating (essentially a clear acrylic spray over the electronics and circuit boards to keep water from reaching them) but do not coat any connectors).
The usual cuplrits are poor seam sealant (as Malcolm said) or leaking wiper buckets, misplaced or missing grommets or blocked drains.
Use sikaflex or tigerseal to redo seams.

 

[dangermose240]

Thanks for replying the information on those seems would be much appreciated
I'll give all the connections gators a good look and make sure the drains are all clear. I would think its got to be something new like a blockage as we have never had it before and have had the car for 8+ years.

Thanks

Chris

 

[xsawgx]

Good info