2005 C320cdi charging issue

[SeeKlassbenz]

Hi to everyone hope u are all well. Iv recently got my first Mercedes and loving every minute dispite the fact it’s been a troublesome time.. Iv searched through the forum and I’m not any wiser regarding my cars issue.. So to get to the point sometimes the alternator doesn’t charge the battery, if I disconnect and reconnect the battery it charges fine, but the first time I turn it off it doesn’t charge anymore, really don’t understand I hope one of u guys have had this issue and can help me resolve it take care everyone and thanks for any reply’s

Paul

 

[DSM10000]

Does the Alternator have an "Exciter circuit"

Some Alternators have these and a poor connection at this part could cause your symptoms.
It could also be a faulty voltage regulator.

"The exciter wire is used to turn on the voltage regulator. This wire, when unplugged, should have approx. 12.5 volts with the key on. If it does not then the alternator will not work."

 

[SeeKlassbenz]

Thanks for that, it’s just strange that it works fine till the first time I turn it off

 

[DSM10000]

Perhaps a visit to an Auto electrician would help?

 

[SeeKlassbenz]

I’m sure I’ll figure it out myself says the guy who just asked the community I do all my own repairs just thought maybe someone would’ve seen this problem before, I thought I had sorted it by following the correct battery reconnection procedure but I’m not that lucky

 

[DSM10000]

I’m sure I’ll figure it out myself says the guy who just asked the community I do all my own repairs just thought maybe someone would’ve seen this problem before, I thought I had sorted it by following the correct battery reconnection procedure but I’m not that lucky

Good luck.

Try removing the Alternator and checking its overall condition along with the Voltage Regulator and brushes.

In addition check out the state of the wiring for damage.

 

[SeeKlassbenz]

Good luck.

Try removing the Alternator and checking its overall condition along with the Voltage Regulator and brushes.

In addition check out the state of the wiring for damage.

Thank you.. I’m friends with the previous owner who replaced the alternator, obviously I’m not taking anything for granted I think my next move is remove alternator and have it properly checked

 

[SeeKlassbenz]

Thank you.. I’m friends with the previous owner who replaced the alternator, obviously I’m not taking anything for granted I think my next move is remove alternator and have it properly checked

Providing I don’t find anything untoward with connections and wiring

 

[markjay]

Does the Alternator have an "Exciter circuit"

Some Alternators have these and a poor connection at this part could cause your symptoms.
It could also be a faulty voltage regulator.

"The exciter wire is used to turn on the voltage regulator. This wire, when unplugged, should have approx. 12.5 volts with the key on. If it does not then the alternator will not work."

I once inadvertently disconnected the exciter wire which on old cars ran though the low charging warning bulb on the dash. After having to push-start the car a few times I finally took it to an auto electrician who explained to me the purpose of the exciter wire.... that was nearly 40 years ago but the lesson learnt has not been forgotten!

 

[DSM10000]

I once inadvertently disconnected the exciter wire which on old cars ran though the low charging warning bulb on the dash. After having to push-start the car a few times I finally took it to an auto electrician who explained to me the purpose of the exciter wire.... that was nearly 40 years ago but the lesson learnt has not been forgotten!

I wasn't driving 40 years ago