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Discussion Starter #1
hi guys - hoping someone can help me here, these are the symptoms of my problem:

i was driving along the motorway when the battery light came on FAINTLY, it was around 2am and raining and i wanted to get home and had about 50 miles to go so pushed on and just made it home, but when i slowed down the oil light started flashing, i presumed that the 2 pin plug had come off the alternator or that the belt had snapped as these would be the symptoms. The next day i tested the battery voltage with the engine running and got about 11.5 volts (so not charging), i then tested the power from the alternator field coil supply (blue wire) and got 10.4 volts and decided that it was the alternator that was at fault rather than the battery and bought a new alternator - this didn't fix the problem so i thought that maybe it was the battery at fault so bought a new battery but this didn't fix the problem either, i am now stumped (and 160 quid lighter!!) as i don't know what the faint battery light signifies (it comes on faint when the ignition is on but the engine isn't running aswel which i found wierd as its normally bright in this circumstance), i know what the flashing oil light means: either the low pressure oil sensor (cylinder head one) isn't getting pressure or is disconnected or there is no rpm signal from the alternator, i am presuming it is the latter as i have drove it for over 200 miles now and the oil light stops flashing when the revs get above around 2000 rpm, i also found that the battery light doesnt come on when the 2 pin connector to the alternator is disconnected???

Does anyone have any idea what is going on with my van??!:*:*:*

Many thanks in advance, Martin
 

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First off check the wires in the two pin connector to the alternator, they are prone to cracking. The blue wire is the wire from the warning light and needs to supply voltage to the alternator to excite the coils and begin charging. If the wires are ok I would be looking to fit a new regulator/brush pack, or an exchange alternator. It is not uncommon for exchange ones to be faulty as well.
 

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Discussion Starter #3
hi upspex, yeah the alternator is new but i have been told that it is not uncommon for them to be faulty straight out of the box (its a pattern item not genuine) and i've been told by a vw mechanic that if you unplug the 2 pin plug from the alternator and the battery warning light goes out then it signifies an alternator fault so i'm gonna swap it with my friends T4 alternator tomorrow and see if this cures the problem, Thanks for the replyT:
 

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Discussion Starter #4
fitted my mates alternator today and its charging fine! so thats a brand new alternator which was faulty straight out of the box, gonna go and feed it to the guy i bought it off of tomorrow...
 
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