Blake Moore

I've got a 2003 S500 4Matic. Lately it's been bitterly cold where I live, and when it gets down into the 30s it wont start. Sometimes if I leave the key in the ON position for a few minutes it will, but it's getting harder and harder. All fuses and relays are good. The windows and Climate Control don't work, either. Unsure about COMMAND, my particular automobile had the head unit and amp removed when I bought it. All the other lights come on. Please advise, the ol lady is getting grouchy about me taking her DeVille everywhere.

Astro14

I would start with a full, complete charge on your battery. You may have a quiescent drain that is exacerbating the cold weather loss of battery performance, or your alternator might not be charging, or your battery may just be weak.

All of your symptoms can be explained by low voltage. So, since the battery supplies voltage, start with that. I recommend an automatic charger that can be set for AGM. If you don't have one, then charge until your battery has a voltage of 12.8v. Slightly less if it's very cold.

You may find this helpful...

http://www.eastpennmanufacturing.com...pdate-1401.pdf