2012 Merc C200 CGI
That said, it's now a 5 year old battery in the car, maybe even a 6 year old battery. Depending on climate and how you drive the car (parked a lot of used a lot), you MAY need a new battery, but I'd start by checking alternator output first.
Welcome to the forum!
Mine is MB C200 W204 Year 2012 (engine M271)
I turned on the fancy feature to monitor the Voltage and Current on the dashboard.
All the lights, AC, radio are turned off.
- Initial battery voltage: 12.3V (I use new AMARON battery in July 2020)
- A while after starting the engine, the voltage drop to 11.5 V ( I think this is normal)
- Afterward, the voltage increase and reach 14.1V (current above 0)
- I start to turn on the radio, AC, and finally lights, the voltage still showing 13.6-13.9 V (current above zero)
- Shift the automatic tranmission lever from P to R, the voltage drop to 13 V (current drop to below zero around -2A)
- Shift again the automatic transmission lever from R to N, the voltage increase to 13.6-13.9V (the current back above zero)
- Shift again the automatic transmission lever from N to D, the voltage drop again to 12.3-12.4V (the current drop and fluctuate between +1 to -20 A)
After driving the car for about five minutes, the red engine warning light flashing and later car stall
After turn off everything, I ignite again and the engine is OK.
But the car will stall again after driving a while (like 5 minutes).
Do I need to replace the alternator for sure?
Thank you
Last edited by Hariandja; Sep 19, 2020 at 05:00 AM.
Mine is MB C200 W204 Year 2012 (engine M271)
I turned on the fancy feature to monitor the Voltage and Current on the dashboard:
- Initial battery voltage: 12.4V (I use new AMARON battery in July 2020)
- A while after starting the engine, the voltage drop to 11.1 V for ver short time( I think this is normal)
- Afterward, the voltage increase and reach 14.8V (current 19 A)
- I start to turn on the radio, AC, and finally all lights, the voltage drop to 13.1 V (current drop to 3A)
- Shift the automatic tranmission lever from P to R, the voltage drop to 12.8 V (current drop to -5.5A)
- Shift again the automatic transmission lever from R to N, the voltage increase to 13.V (the current going up to 9A)
- Shift again the automatic transmission lever from N to D, the voltage showing 13 V (the current drop to 2A)
- Shift back again the automatic transmission lever from D to P, the voltage showing 13.6 V (the current drop to 10A)
After driving the car for about five minutes, the red engine warning light flashing and later car stall
After turn off everything, I ignite again and the engine is OK.
But the car will stall again after driving a while (like 5 minutes).
Do I need to replace the alternator for sure?
Thank you0






