Brand new alternator battery light off/on

[jordang78]

Hey all i got a 2012 cjaa tdi i just replaced the alternator and my battery light appears quite often while driving mostly on the freeway its on then a couple seconds later its back off for a couple minutes and just changes back and fourth. Ive tried reading the codes but no codes for the alternator and for the most part when im driving its at a constant 13.6 or right at 14 never has dropped below 13.5 and never higher then 14 volts it seems that it comes on when it hits 14 volts but its so random i cant just pin it too overcharging and i know its not under charging the battery cause thats only 3 weeks old sorry for the long post im just confused on what it could be all the connections were cleaned and are tight. Any help would be appreciated and agian sorry if its alittle confusing and long

 

[Seatman]

Stick a meter on the alternator and see what it's actually putting out, could just be a faulty alternator from new. If that's ok then check across the battery terminals, see if it matches. If not there must be a bad connection or bad cable between them.

 

[Mozambiquer]

Hey all i got a 2012 cjaa tdi i just replaced the alternator and my battery light appears quite often while driving mostly on the freeway its on then a couple seconds later its back off for a couple minutes and just changes back and fourth. Ive tried reading the codes but no codes for the alternator and for the most part when im driving its at a constant 13.6 or right at 14 never has dropped below 13.5 and never higher then 14 volts it seems that it comes on when it hits 14 volts but its so random i cant just pin it too overcharging and i know its not under charging the battery cause thats only 3 weeks old sorry for the long post im just confused on what it could be all the connections were cleaned and are tight. Any help would be appreciated and agian sorry if its alittle confusing and long

What brand of alternator was installed?

 

[jordang78]

Sorry for the late response its a ultima from O'Reillys drove it for another day and the alternator ending uo just being bad swapped it out two more times and then ended up going with a bosch and its all good now

 

[Mozambiquer]

Sorry for the late response its a ultima from O'Reillys drove it for another day and the alternator ending uo just being bad swapped it out two more times and then ended up going with a bosch and its all good now

That's sadly all too common. Part of the reason I started rebuilding them myself.

 

[Dannyboy]

I'll second Moza.

I've noticed a string of crappy alternators recently on mk5/6s, especially aftermarket. Even OEM rebuilds are becoming terrible.
I've rebuilt my 2014s already and it's only had 78k kms when it started acting goofy. At 108k now and no issues

My touareg had an alternator change nearly 3 years ago (X part number)by previous owner and it stopped working last December, slip ring was worn completely down to the plastic backing. Copper used was very soft. And this was an OEM rebuild

 

[Mozambiquer]

I'll second Moza.

I've noticed a string of crappy alternators recently on mk5/6s, especially aftermarket. Even OEM rebuilds are becoming terrible.
I've rebuilt my 2014s already and it's only had 78k kms when it started acting goofy. At 108k now and no issues

My touareg had an alternator change nearly 3 years ago (X part number)by previous owner and it stopped working last December, slip ring was worn completely down to the plastic backing. Copper used was very soft. And this was an OEM rebuild

Bosch got bought by a Chinese company SEG a couple years back, many of their parts are now made in China.
On your Touareg one, didn't have any oil or fuel that leaked on it?
Thats the biggest thing that causes the slip rings to wear out.

 

[Dannyboy]

Bosch got bought by a Chinese company SEG a couple years back, many of their parts are now made in China.
On your Touareg one, didn't have any oil or fuel that leaked on it?
Thats the biggest thing that causes the slip rings to wear out.

Nope. Just both wore very quick. When I mean the copper was soft, it was very soft. Normal commutator copper has a 'shiny' appearance when it's wearing normally. This had a very dull, matt look to it. Also one wore quicker than the other.

 

[Mozambiquer]

Nope. Just both wore very quick. When I mean the copper was soft, it was very soft. Normal commutator copper has a 'shiny' appearance when it's wearing normally. This had a very dull, matt look to it. Also one wore quicker than the other.

Yeah, that sounds off. I've always kinda wondered who does the rebuilds for VW. I do a ton of those touareg, q7 and Cayenne alternators, and get the oem Valeo slip rings, which is what I would assume the vw reman ones used, but you never know.

 

[Dannyboy]

Yeah, that sounds off. I've always kinda wondered who does the rebuilds for VW. I do a ton of those touareg, q7 and Cayenne alternators, and get the oem Valeo slip rings, which is what I would assume the vw reman ones used, but you never know.

Yeah I couldn't say. It was a oem rebuilt alternator as far as I know. If I had known you sell parts I would have bought the rebuilt parts from you

I'll be sending a message for some parts soon, my son's 2010 golfs cjaa alternator is starting to act funky when a high load is place on it during very cold mornings when the PTC aux heater is on.

 

[Mozambiquer]

Yeah I couldn't say. It was a oem rebuilt alternator as far as I know. If I had known you sell parts I would have bought the rebuilt parts from you

I'll be sending a message for some parts soon, my son's 2010 golfs cjaa alternator is starting to act funky when a high load is place on it during very cold mornings when the PTC aux heater is on.

Yeah, I've got pretty much all the parts for any of them, as well as new units. Right now I've got a special on new oem CJAA alternators. $285 plus shipping.