electrical drain 97E320

Hi guys: Need your help! I have a 97 Mercedes E320, low miles & garaged. The brand new battery keeps draining down when car sits for 5 or more days. I used a test light between the negative pole of the battery and
the cable. The light goes on. I pulled each fuse,one at a time, under hood and rear seat, and light still stays on. Everything was shut off and no lights were on. Could it be in the security system, and if so, how do I check it--or what other test or solution could I do. Your help may save my sanity. Thanks
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There's a fuse box on the left front fender - did you also pull those?
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Thanks TG for your reply. If you mean under the hood (drivers side) yes I did, with the same results. Are there more than two fuse boxes?
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Only two fuse boxes that I know of. Suggest you repeat the test procedure except to put the test light in place of each fuse as you proceed through the fuse population. That will show the drain of a specific circuit.
There have been instances - generally, not specific to this model (which I also own) - of the trunk light draining the battery. A simple test would be to temporarily remove its bulb.
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Thanks again TG. I pulled fuse #3 which controls the trunk light, but I'll take it out. I'll try the test again this weekend, and let you know. Thanks.
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Don't overlook the possibility that the "new" battery is defective.
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If the test light is illuminating, then something is drawing current, but that doesn't rule out the battery.
John
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Sandro69, The test light trick for finding drains on a battery is a great tip for older cars, but on the new computer controlled cars it can cause misdiagnosing. When power is applied to the car, some of the computers will go through a reset, then 'go to sleep', so to speak. There is not enough current through the test light for these computers to reset but they will try. Thus, the drain doesn't go away. Delayed interior lights will do the same thing. Now I am not a MB expert, but I have been working on the electrical system on domestic and Asian cars for many years. Some cars will take as much as 15 min to reset and then 'go to sleep', but will never 'go to sleep' using a test light. You must use an amp meter on these cars.
Paul Paul's Auto Electric

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Thanks! Good to know.
Marty
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