Not starting and finally dead (JIM)
Thread Starter
Junior Member
Joined: Nov 2010
Posts: 25
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From: Texas
2010 S 550
Not starting and finally dead (JIM)
2010 S550 ,164k miles (not 4Matic)So for te past couple of months, on a rare occasion it would not start, just nothing. Nut all dash functions were lit as it is every time you start up. After a while (hours) tried and would start. Would go a few weeks and it happened again. Note the battery and starter were replaced in the past year. Today I go to start. It does start. But pretty much every message that is visible on the screen pops up. I switched off ignition and it t would not start. We were leaving so I could not investigate. Retuned home five hours later. Notice a single bulb is glowing in the rear tail lights on both sides. Entered the car and nada. No lights, no sound, nothing, just a pitch black screen where the speedometer is. None of the car's interior lights came on either. And pressing any of the key fob buttons did nothing. Tried as a manual switch on but again crickets. Any suggestions? I am thinking perhaps battery is dead but will wait until tomorrow to try to jump it/
Suggestions appreciated. TIA
Suggestions appreciated. TIA
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,322
Likes: 1,678
S500
never assume ANY battery is in a serviceable condition - even if you have 5 new ones fully charged one to fit - check, don't just believe one might work correctly
never try to do diagnostics without serious battery support - they need 37 amps key on lights off !!!!
as a min throw 6 amps at with a charger whenever you have a key on and turn off as much as you can...
do a diagnostic scan laugh at the half a million codes since the day it was made and no one ever had the kit to clear - take a photo of any that might be connected - delete everything and start over
when that provides zero help
then you go bit by bit and check things
water ingress
earth points
mouse damage
lose connections
and on and on and on.....
or easier ring up the scrap yard and do you self a favour
never try to do diagnostics without serious battery support - they need 37 amps key on lights off !!!!
as a min throw 6 amps at with a charger whenever you have a key on and turn off as much as you can...
do a diagnostic scan laugh at the half a million codes since the day it was made and no one ever had the kit to clear - take a photo of any that might be connected - delete everything and start over
when that provides zero help
then you go bit by bit and check things
water ingress
earth points
mouse damage
lose connections
and on and on and on.....
or easier ring up the scrap yard and do you self a favour
Junior Member
Joined: Dec 2021
Posts: 69
Likes: 25
From: Al Raha Beach. Abu Dhabi
Silver 2013 S500 AMG. 4.7 litre V8 Bi Turbo 7 Speed Gearbox
Hi Bohaiboy, It sounds like a very dead battery to me.
I would start with a multi meter and check the battery voltage when it is disconnected from the car, then when it is connected to the car and then when the engine is running.
A healthy battery, NOT under load should be sitting around 12v. Connected to the car and with the engine not running, it might be sitting under 12v as some the car componenets may be drawing on it and dropping its cvoltage.
With the engine running, it should be well above 12v, maybe 13v or more volts, indicating that the generator is supplying sufficient voltage to recharge that battery while the car is running.
This basic information may help you diagnose where the problem is. Very low battery voltage, dead batt, or no charge. Low voltage across terminals while engine running suggests generator not sending voltage to the batt. Good voltage across the terminals with engine running, probably dead batt, that will NOT accept recharging volts = time for a new batt...
PS> I am not a mechanic or auto electrician. Just the steps I would take to try and work out where the problem is, before spending money.
Good luck
I would start with a multi meter and check the battery voltage when it is disconnected from the car, then when it is connected to the car and then when the engine is running.
A healthy battery, NOT under load should be sitting around 12v. Connected to the car and with the engine not running, it might be sitting under 12v as some the car componenets may be drawing on it and dropping its cvoltage.
With the engine running, it should be well above 12v, maybe 13v or more volts, indicating that the generator is supplying sufficient voltage to recharge that battery while the car is running.
This basic information may help you diagnose where the problem is. Very low battery voltage, dead batt, or no charge. Low voltage across terminals while engine running suggests generator not sending voltage to the batt. Good voltage across the terminals with engine running, probably dead batt, that will NOT accept recharging volts = time for a new batt...
PS> I am not a mechanic or auto electrician. Just the steps I would take to try and work out where the problem is, before spending money.
Good luck
