E350 charging problems
Discussion
2015 E350 71k miles
Whilst driving a schematic of a battery came up on the speedo display saying "Consult drivers manual".
Checked the battery voltage with multi meter 12v with engine off and 11.6 with it on .
The auxillary battery is about 2 years old also a Varta
Had to wait a week before the local Maidstone INDY could take the car in and they said it was the alternator. He said that aftermarket ones "don't last long in a mercedes" and therefore should fit a genuine one , £620 + vat plus fitting, just over £1200 !!!!!
So after another few days my wallet had been lightened and I got the car back. All seemed ok until I spent a short time with just Command on to input some sat nav destinations, then Command shut down unless I started the engine.
Ran the engine for 5 minutes, turned it off and after 10 mins Command shut down. The battery at this point was showing 11.9V with engine off and over 14v with it running. So charging.
During the course of all this I refitted the original battery yesterday, had charged it to 12.9V Took the charger off last night 12.9v with engine off.
Aso this morning battery is down to 11.9V, now on charge (engine will still start)
I noticed that when refitting the second (negative) battery terminal connection that there was a slight spark from the terminal .
Everything was turned off, key out and doors shut at this point.
I'm thinking the there is a parasitic drain on the battery.
I will be very gratefull for any suggestions
Thank you
Whilst driving a schematic of a battery came up on the speedo display saying "Consult drivers manual".
Checked the battery voltage with multi meter 12v with engine off and 11.6 with it on .
The auxillary battery is about 2 years old also a Varta
Had to wait a week before the local Maidstone INDY could take the car in and they said it was the alternator. He said that aftermarket ones "don't last long in a mercedes" and therefore should fit a genuine one , £620 + vat plus fitting, just over £1200 !!!!!
So after another few days my wallet had been lightened and I got the car back. All seemed ok until I spent a short time with just Command on to input some sat nav destinations, then Command shut down unless I started the engine.
Ran the engine for 5 minutes, turned it off and after 10 mins Command shut down. The battery at this point was showing 11.9V with engine off and over 14v with it running. So charging.
During the course of all this I refitted the original battery yesterday, had charged it to 12.9V Took the charger off last night 12.9v with engine off.
Aso this morning battery is down to 11.9V, now on charge (engine will still start)
I noticed that when refitting the second (negative) battery terminal connection that there was a slight spark from the terminal .
Everything was turned off, key out and doors shut at this point.
I'm thinking the there is a parasitic drain on the battery.
I will be very gratefull for any suggestions
Thank you
Metric Max said:
I'm thinking the there is a parasitic drain on the battery.
Could be. I suppose that before reconnecting the battery lead, you could switch your multimeter (assuming that's what you've used to measure the voltage) and its connections into current mode and connect one lead to the battery terminal and the other to the battery lead and see what current is flowing.Although i use my meter to check voltages (usually on AA batteries) and for checking continuity of a circuit I seem to be crap at measuring amps.
Should have paid more attention at school all those years ago.
However I have a mate who knows what he's doing coming later with a meter.
Will report back in the morning
Should have paid more attention at school all those years ago.
However I have a mate who knows what he's doing coming later with a meter.
Will report back in the morning
OP Post back with outcome!
This is an "usual suspect" issue.
(1) Voltage Regulator on Alternator - IT'S a WEARABLE PART costing £70+vat. Merc alternators are bullet proof.
or
(2) Electrical short - check for dampness in the carpets and then google what is underneath.
Lots of YouTube videos about applying the Multi-meter in series with the battery and then unplugging fuses and re-plugging to check for current drain.
I had two cases
A Class W169 - phone module short underneath passenger seat due to cabin filter clogging with leaves.
E Class W211 - voltage regulator replacement.
This is an "usual suspect" issue.
(1) Voltage Regulator on Alternator - IT'S a WEARABLE PART costing £70+vat. Merc alternators are bullet proof.
or
(2) Electrical short - check for dampness in the carpets and then google what is underneath.
Lots of YouTube videos about applying the Multi-meter in series with the battery and then unplugging fuses and re-plugging to check for current drain.
I had two cases
A Class W169 - phone module short underneath passenger seat due to cabin filter clogging with leaves.
E Class W211 - voltage regulator replacement.
I'm not sure if it applies to this specific model but some Mercedes have a coupling crank pulley that can fail and give charging issues, you can have situations of intermittent alternator charging, the aux belt will still be seen to be running but its not applying enough torque to the alternator.
To check, remove the aux belt and check the pulley by hand to make sure it locks up correct under load
To check, remove the aux belt and check the pulley by hand to make sure it locks up correct under load
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