How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask FIXITMAN Your Own Question
FIXITMAN
FIXITMAN, Master Technician
Category: Mercedes
Satisfied Customers: 17198
Experience:  ASE MASTER CERTIFIED, AA DEGREE DIESEL/AUTOMOTIVE
1627031
Type Your Mercedes Question Here...
FIXITMAN is online now
A new question is answered every 9 seconds

Check battery alternator light came on. Batter was replaced

Customer Question

Check battery alternator light came on. Batter was replaced last year. Can I test the battery and alternator separate? Car idles rough when engine is cold. Advice?
Submitted: 1 year ago.
Category: Mercedes
Expert:  FIXITMAN replied 1 year ago.

Hello, my name is Bobby. Thank you for the question. Can you tell me if you have a voltage meter to run you through some tests? If the battery light is on when the engine is running then chances are you have an alternator that is failing.

Customer: replied 1 year ago.
I don't have any tools. I'm trying to get some direction before I go to the shop?
Expert:  FIXITMAN replied 1 year ago.

Thanks for the response. If the car is starting fine then the battery should be just fine. The battery light coming on when the engine is running indicates a bad alternator. I would always check the battery connections first. If those are clean and tight then it is probably the alternator.