The SOS light won't go off in my 2000 Mercedes S430 and now my battery has ran down. Could the sos be the result of the dead battery?

The battery is dead or the alternator needs checking or the earth lead has disconnected.

http://www.autozone.com/batteries-starting-and-charging/starter/mercedes-benz/s430/2000/8-cylinders-4-3l-mfi

Pull it with nose pliers , probably damaged magazine .

you have to stick the key in the trunk and turn it to the lefy while hittin the unlock button on the key pad 35 times has to be 35 and it will unlock. my battery died and it locked the trunk as u know i coudn't jump it cause the battary is in the trunk haha but yeah 35 times while hitting the key. mercedes wont tell u but my buddy works for inskip and filled me in your o so welcome from one s430 owner to another

the auto parts house lends tools get a code reader from one n get the trouble codes itll have instructions that will give you a starting point autozone does this with a deposit on the tool and they can help read the codes if they cant find an explination for one its a dealer code and the service writer at the dealer will help you on the phone

Call someone in service dept at a mbz dealership. They can input your cars vin number and tell you if that car has battery connections under the hood. My 2000 s430 doesnt have any under the hood.

To the best of my knowledge it should not need to, consulting your dealer or a call to a local Mercedes repair shop would give you the best answer. I would say co-incidence that switch went bad at same time of dead battery

and i am thinking lack of ground to the dash and steering column, seems to explain more

there should be jump ports under the hood if you hook up a set of jumper cables to them it will give you the power you need to open the truck to replace to battery.

ECM ( Electronic control Module ) may have failed. Posible low fuel Presure. Maybe mass airflow sensor