1995 E320 Wagon electrical problem - PeachParts Mercedes-Benz Forum

FLYGEEZER · #1 12-02-2010, 01:29 PM

After a day trip in the rain, without problems, parked the car in the driveway only to find the next morning a dead battery. Put the charger for an hour,had a coffee to give it another try. Once in the car I heard a "ticka-ticka noise comming from the passenger footwell. Removed the mats and the cover to discover the noise comming from the ECU? Anyway the shinny metal box on the right. Sounds like a chattering relay. It only quits when the battery is disconnected from the system. Can this be a rain induced short to ground or is something being powered thru a water contact from some insulation breakdown The current draw while this "chattering" is occuring is about .75 amp. This has happened several times over the past years. The dead battery thing after driving in intense rain. Car dried out in the past and no more problems until this soaker. I need a place to start. Any help will be very much appreciated. No water in footwell or any other place thats is obvious.

FLYGEEZER · #2 12-05-2010, 02:20 PM

Found the problem. Rain gutter below the windshield and above the battery compartment is made from several connecting pieces. One of the connections or seams is directly above the OVP. During the troubleshooting I removed the OVP and found it full of water that had dripped from the ill fitting seam. Replaced the OVP, attached a plastic bag (raincoat) over it and applied windshield sealant over the seam. I've heard of many different problem caused by a bad OVP. Don't ever dismiss it when electrical problems occur. I'm going there first for any malfunction......maybe even a flat tire!
All the best to everyone.

thayer · #3 12-06-2010, 07:18 AM

It's always the ovp

or the wiring harness, or the fpr, or the evap, or the combo switch.

glad you fixed it. The raincoat is a great idea...I'll slide one over mine too.

Cheers