My uncle showed up at work experiencing issues with his electrical system on his S430. The SRS system was showing all kinds of codes and his tail lights remained on even when switched off (and you could not turn them off)
He made it to work, but once he shut the car off it would not start again. I pulled the battery cable to save the battery, but at first I couldn't determine the problem.
I then put my hand down on the passenger side floor board and noticed it was soaking wet. After doing some research they put a fuse box on the floorboard (real smart engineering).
The guy at the shop said that pollen had clogged a drainage hole in the engine compartment. It rain the night before and evidently the water ran into the passenger compartment flooding the floor board. Has anyone experienced this?
He made it to work, but once he shut the car off it would not start again. I pulled the battery cable to save the battery, but at first I couldn't determine the problem.
I then put my hand down on the passenger side floor board and noticed it was soaking wet. After doing some research they put a fuse box on the floorboard (real smart engineering).
The guy at the shop said that pollen had clogged a drainage hole in the engine compartment. It rain the night before and evidently the water ran into the passenger compartment flooding the floor board. Has anyone experienced this?
Super Member
This problem is caused by the drainage plug on the pic getting clogged. Leaves and dirt gets in that AC suction vent area and clogs the drain plug and once the water tops out, it has nowhere else to go but inside the car following the AC duct system. I experienced this on my 2000 S500 and that was a very painful experience. Open the hood, gently pull that plastic covering, stick your finger through there and feel for the plug at the bottom. Once you locate the plug, unclog it and push it all the way down to relieve the water. Now for the damage. Once water gets in the system, it corrodes the electric system. You will need to remove your rear seat and expose the rear SAM that has all the fuses and check for corrotion. It may or may not be visible by just looking. It has probably corroded and makes your rear lights stay on. Your defrost will probably not be working either, your soft doors not working and everything else controlled from that SAM. My suggestion is unplug the battery to avoid further corrosion of the electric system. Your Rear SAM may need to be replaced once it has corroded. The more you drive or try to, the more damage you cause. If you can't do any of these, then take the car in for repair. It sucks but it happens.
Member
Had the same prob once, and it totaly messed up my AC fan 
1300$ to change it !
1300$ to change it !
