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i have a 02 b5 v6 2.8 front wheel drive that the alt is not charging the batt when the car is running i tested the system at the batt and it is at about 12.2 i was told it should be over 13 to charge the batt the alt is brand new only a month old and the batt is new as well also if i remove the pos batt cable when the car is running and it still runs also the pos batt cable gets hot i had the system tested a ORAP and they said the alt is onl;y putting out 11 not enough to charge the system there are no lights on in the dash the last time the alt went out i got a light in the dash for the batt but not this time also the car has 250k on it if there is any more info i could share let me know if you can help thanks
 

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Discussion Starter #2
i also checked all the fuses inside the car one at a time all were good and the batt cable ends look good no corr. also when the car is running the the metter goes doen from like 12.5 to 12
 

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Never disconnect battery cable while vehicle is running

You more than likely have a bad battery cable as it is corroded inside which is very common as I've seen more alternators and starters replaced over the years and end result is the same as corrosion inside the cable was the actual problem ... It could be either cable and don't forget to clean end of ground cable where it attaches ... A way to test it is car running with volt meter on battery try moving cable around and see if voltage changes... Also you should never remove battery cable with vehicle running as you can burn out the diode pack inside the alternator not to mention the risk of a voltage surge which can fry all your electronics such as computers ,relays , and radio... The fact that the cable is getting hot tells me that the cable has high internal resistance thus the heat you are feeling , I would bet that the internal cable is white from corrosion if you were to remove the insulation...

:wrench:
 

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ok thanks i have 2 cables going to the pos side and i am not shure where they go one looks like it goes thru the fire wall and the other ? is there a web site i can go to that will show me this and i hope there might be a trick to replacing it because the alt took like 7 hrs start to finish also is there a web site i could see what number fuses are what when i bought the car it did not come with a manual
 

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I was looking for some help with a headlight issue I'm having and found this fuse diagram on here. http://shakti.trincoll.edu/~sritchie/Passat_fuse_panel.html

Might help you out. I'm also looking for a good manual. My car was on a certified pre-owned extended warranty until recently so I'm just now looking at the DIY portion. I had a lot of charging issues myself, but it turned out to be more the VW dealership not having a clue and just replacing parts.

Best of luck,
Matt
:banghead:
 
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