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 Matt Your Own Question
Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22744
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your Mercedes Question Here...
Matt is online now

Hi I have 220 cdi 2002 top range battery fitted 14 ago had

Customer Question

Hi I have 220 cdi 2002 top range battery fitted 14 ago had tested perfect alternator has been off and tested 3 times no faults found still not charging any ideas. Thanks
Submitted: 3 years ago.
Category: Mercedes
Expert:  Matt replied 3 years ago.

this sounds like the alternator to ECU connection is faulty or the ECU has a problem as the alternator is switched over to charge by the ECU

I'd start by tracing the small wires from the alternator back to the ECU checking for damage and corroded connections

if this is OK then

also check that the alternator is secure to the engine as this provides the ground for the charging circuit and make sure that the engine / gearbox earth strap is secure and the contacts are clean and bright.

and if thats ok thenI'd consider sending the ECU off for testing

both of these firms are very good