97 passat. Battery light staying on.

[passatin]

Have a 97 passat tdi. Battery went bad as it failed a load test. Just replaced battery and when it is running the battery light on the cluster stays on red. Only started it and let it run for a couple minutes and turned it off. Light stayed on...

is it an alternator?

If it is the alternator then does the serpentine belt need to come off as well?

Is this a do it yourself job?
Any ideas?

thank you.

 

[Abacus]

The alternator is an easy job. The serpentine belt just needs to be released, not come off completely.

 

[sundevil36]

The write up for the alternator re & re by wingnut (think it was his write up) is an excellent post with tons of photos. Helped me do mine twice. Take your time and you'll be 100% good. Also, you can see if the alternator is putting out ~12.6v with a test meter.

 

[ZachdkingNH]

Sounds like your alt...same thing happened to my B3 more or less. Testing with a multimeter and Replacing it is an easy DIY, but if you buy a reman one you're looking at close to $300, try to find one off a wreck or from a yard or wherever. One more thing to consider is that I believe your tach gets its' signal from your alternator, while there are alternators that will fit and serve your purpose, if you want to keep your tach be sure that your replacement has the right plug for your tach.

 

[ToddA1]

The alternator should be putting out more than 12.6V, more in the neighborhood of 13.5V+.

Unless the bearings are bad, it's typically the voltage regulator that goes bad in these.

Tach signal comes from the ECU, not the W terminal, like an IDI. If your B3 was converted and has a 1Z, it's a TDI. IDIs are TD.

-Todd

 

[twentyeight]

If you can find a set of brushes they're not hard to replace inside the alternator.

 

[vanbcguy]

Though 9 times out of 10 if the brushes are worn to the point that they aren't making a connection any longer the slip rings are in pretty bad shape too...

Sent from my XT1097 using Tapatalk

 

[passatin]

Tested it out with a multi meter and its putting out nothing.


thx

Replaced the alt. Never hated that car so much. 3 hours to get it back on....


No battery light!!! Makes leaving the drivers window up all the time seem not so bad.

 

[Clean1zpassat]

When my alternator went. This was the symptom exact. Id say its your issue. Easily replaced.