Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
My battery drains while the car is turned off. I recharge the battery fully, and it's dead after about 5 days with NO driving. Obviously it lasts longer if I drive it every day.

Today we measured the current through the battery (-) terminal and the ground cable (with the positive cable connected to the battery (+) terminal.)

There is a current of about .02 mA with the car OFF and nothing at all on. (The ammeter is on the 0-3 setting.)

I opened the fuse box and tried pulling them out, individually. On my grandfathers suggestion, I pulled out #9:

diagnostic term.6, hazard warning system, clock, front roof light, radio, vanity mirror light, relay comfort circuitry term.86
With #9 out the current is zero. ONLY removing THAT fuse makes the current zero.

My question: what should I do next? FWIW, I did have a problem with the alarm going off before and took the alarm box wires out and then put them back. And there is a periodic clicking under the passenger-side carpet (where the alarm is).
 

·
Registered
Joined
·
269 Posts
Sounds like the alarm could be draining the battery. My first thought was the battery is pooched as well, have the battery and alternator tested. That should always be your first test.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #4
The battery is new, the alternator was recently replaced.

Having the alarm fixed would be expensive...maybe I can rig a switch between the cable and the battery so I don't have to open the hood every time I want to use the car...
 

·
Registered
Joined
·
269 Posts
Remove the alarm, or bypass it. It seems you have at least a basic knowledge of wiring and currents, find out what needs to be bypassed and do it. Then kill the power to the alarm. If the relay is clicking from time to time that means the alarm is still active.
 
1 - 5 of 5 Posts
Top