That's great but not going to answer anyone's questions if they have the same problem.

 

Likely its the AUX battery by the cabin filter causing the red warning.

 

I was under the impression this would not cause the red warning as long as the main battery is within spec.

 

no nope nein…they are independent …the AUX battery is monitored separately, if the voltage at the battery terminals is over 12.2 vdc and you still have the red warning, there is a fuse hidden on the (+) wire about 3 inches down. If the red warning is intermittent then the AUX battery is shot.

 

I Beleive Its Fixed I Went Into THe Back End Of The Computer & The Citcuit WAs Set To On, Turned It Off & No More Low Convience Lights & No Low Battery & Car Starts Up 1st Try Thanks So Much

 

Thanks. Learning very slowly here but learning none the less. I found that fuse, struggling to get it apart. There is a fuse inside that little plastic piece???

 

I'm struggling with this. Is this real? Back end of the computer?

 

It's not this is it?

 

I am back in this thread. 2005 W211 is draining battery quickly, matter of days. Cannot find the source. Thoughts?

 

The Battery Is Probably Dead Go Into The Computer And Make Sure The Aux Is Set To Off

 

In my case, it was rain
water leak at the antenna wire grommet at the base of the back window that caused a short in some electrical module located there. It also illuminated the left side parking light and let water into the well on the left side of the trunk. Stopped when it dried out.

 

Hi Guidetaf, wish this were the case. New batteries, both of them!

Only workaround for now is disconnect main battery when I park the car for more than a few days.

 

What about a battery tender. I have one permanently attached to the battery in the trunk, plug it in when parked.