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Stan, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3526
Experience:  Technical support engineer
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Accidentally shorted out my alternator on my W203 C220 cdi

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Accidentally shorted out my alternator on my W203 C220 cdi and now I have no power at the alternator so also no charge. Checked all the normal fuses and also the pre fuses near the battery but all ok. Does the power go via the starter? Have power there but that seems to be where it stops. I am lost for anything more to do and really need some guidance before I go nuts.
Stan :

You are right that main alternator cable is unfused 25 square mm line running to the main starter connection

Stan :

There must be battery voltage at the cable on the alternator side. Measure the voltage against battery ground. If you have voltage at the starter, it means cable from starter to alternator is faulty.

Stan :


Customer: Is it possible to replace the cable without removing starter motor as the connection is behind the solenoid. If cable turns out to be ok. Is there something in solenoid that could have burnt out. My starter works fine and have full power to it. Just a residual 2.2 VCD at alternator end.
Stan :

I do not see a reason why the alternator cable cannot be removed without removal of starter.
Actually, the cable has a built in fuse. It is not available separately.

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