ML350 Wont Start

Boardgod

New Member
Joined
Sep 10, 2009
Messages
3
Reaction score
0
Location
London
Your Mercedes
ML 350
I have a 2004 ML 350, 40k miles full service history with Mercedes.

Have had no issues with the car until two days ago when I attempted to start the car, there was a click but it did not turn over.

Jump started the car, noticed the radio was requesting a code, assumed the battery was flat. Drove the car for 30 minutes to charge the battery. turned engine off, would not re-start. No power to open windows or turn heater fans on. attempted to jump start the car again but get a Start Error message, when i remove the donor battery I get no message just a click noise.

I removed the battery to allow it to be slow charged but also give me access to all the connection cables. The battery was charged an a slow charge for nearly 12 hours, the voltage recorded after the charge period was 13.16 volts, as expected it dropping to 12.86 volts one hour later and by 12 hours the voltage was 12.6 volts, 24 hours later the voltage was still 12.6 volts. I have checked the connecting cables at various points without any shorts or connection problems.

I put the battery back into the car. When I attempt to start it there is a click but nothing, I am not sure if the click is from the relay (in the fuse box) or the solenoid on the starter motor. The interesting thing I did not get a Start Error displayed but if I hold the key in the start position, after the click, the side lights come on until I release the key.

- suggestions as to the fault and possible resolution
 

Cole@MBS

Forum Supporter
Authorised Forum Supporter
Joined
Dec 1, 2008
Messages
13,702
Reaction score
950
Age
54
Location
Southampton
Website
www.mbssouthampton.co.uk
Your Mercedes
124 300 CE 24 Coupe, C220CDI, Porsche 911 4s, Dolomite sprint,
Two things come to mind, lower earth strap under the o/s engine mount or the das unit has gone down, both common on the ML,

Welcome to the forums!
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Welcome to the forum,, turn the headlamps on and have someone watch the headlamps when you turn the key to start and see if the headlamps go out
 

jberks

Senior Member
Joined
May 12, 2004
Messages
11,153
Reaction score
41
Location
M1, Outside lane, somewhere between Leeds and Lond
Your Mercedes
Jaguar XF 3.0 S, LR Freelander 2, Fiat 500 & Fiat Panda
Where did you attach the battery when you jump started it?
Was it on the original battery terminals?
Assuming so, then whilst the battery may show 12.6v unloaded, how is it handling any load?
It could just be as simple as a duff battery.
 
OP
B

Boardgod

New Member
Joined
Sep 10, 2009
Messages
3
Reaction score
0
Location
London
Your Mercedes
ML 350
  • Thread Starter
  • Thread starter
  • #5
Update

Where did you attach the battery when you jump started it? To the original battery terminals.

The battery was in the car for 24 hours, so last night I have checked the voltage at various points :-

Connect volt meter across battery after being in the car for 24 hours reported 10.36 volts

Connect volt meter across battery and hit the starter. reported a voltage of 9.55 volts

Recorded voltage at the fuse (terminal 50) during start peaked at 9.97 but it varied as low as 9.36 on four tests.

Also put 9 year old son in car to turn key whilst i listened for the click, it is coming from the starter motor rather than the fuse box - not sure if this helps?
 

jberks

Senior Member
Joined
May 12, 2004
Messages
11,153
Reaction score
41
Location
M1, Outside lane, somewhere between Leeds and Lond
Your Mercedes
Jaguar XF 3.0 S, LR Freelander 2, Fiat 500 & Fiat Panda
Where did you attach the battery when you jump started it? To the original battery terminals.

Connect volt meter across battery after being in the car for 24 hours reported 10.36 volts

Connect volt meter across battery and hit the starter. reported a voltage of 9.55 volts

Recorded voltage at the fuse (terminal 50) during start peaked at 9.97 but it varied as low as 9.36 on four tests.

Also put 9 year old son in car to turn key whilst i listened for the click, it is coming from the starter motor rather than the fuse box - not sure if this helps?

Battery is shot IMHO.
If another battery connected to the same terminals was enough to get it started, that rules out wiring and earth strap issues.
Mercs are funny with low voltage. Whilst most cars still churn over, albeit very unhappily - mercs just click and do nothing.
You may also have a fault thats dragging it down but given it wouldn't start even after an off car recharge, I'd start with a new battery and then keep an eye on it for a couple of weeks so see if the problem comes back.
 
Last edited:
OP
B

Boardgod

New Member
Joined
Sep 10, 2009
Messages
3
Reaction score
0
Location
London
Your Mercedes
ML 350
  • Thread Starter
  • Thread starter
  • #7
fixed

had battery tested - it was faulty !

thanks for the help
 

d:class automotive are specialists in automotive interiors and upholstery. From Mercedes and modern cars to custom and classics. Tel: 01483 722923 Email:info@dclass.co.ukWeb:www.dclass.co.uk
Top Bottom