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Battery/Alternator Visit workshop.

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Old Dec 28, 2019 | 08:29 AM
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W203 C180k 2005
Angry Battery/Alternator Visit workshop.

Hi. I have a C180 Kompressor Sports Coupe 2005 plate with 80k on clock.
I received the Battery/Alternator Visit workshop message a few weeks ago and decided to install a new battery and a refurbished alternator which was as good as new. Everything was fine for 2 weeks until once again the messaged appeared while i was out parked up. I got the car home and reseated the alternator to make sure i did the job correctly with no success. I charged the battery overnight, checked all visible connections for corrosion which there wasn't at all and tested with a multi meter and this is what i got.
Engine off = 12.6V
Engine on = 12.3V
Alt+ > Alt- = 12.3V
Bat- > Alt- = 3.8mV
Bat- > Mount- = 3.8mV
bat+ > Alt+ = 0.1mV - 0.2mV
Do these readings look normal and what other tests can i perform?. I am thinking connecting the bat+ to the alt+ with my jumper lead, would this be wise?
Oh and i did receive the P0620 Generator control circuit code each time.




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Old Dec 30, 2019 | 07:27 AM
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W203 C180k 2005
theres a cable that runs from the battery+ to the starter and then from the starter to the alternator bat+. on some models there a high amp fuse built into the cable running from starter to alternator, thats probably why the car starts and runs but does not charge and im only get mili volts from battery+ to alterantor bat+.
Would it be safe to connect my jumper lead from battery+ to the alterator+ to bypass and see if im right without braking anything?
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Old Dec 31, 2019 | 10:51 PM
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Something is not right. With engine running, battery voltage should be over 13V. Bad alternator?

Are there any modifications on this vehicle?
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