Author Topic: Not charging, no battery light (Read 6597 times)

bvolks73 · « **on:** April 22, 2008, 10:48:54 pm »

I started up my brother's 90 TD Jetta yesterday for the first time since last fall and it's not charging. The battery light doesn't come on at all, even when I first turn the key on before I start it. I checked all the connections and it's getting fire to the alternator through the big cable and fire to the exciter wire. What could be wrong?

truckinwagen · « **Reply #1 on:** April 22, 2008, 11:03:24 pm »

I had that happen and it was that the alternator wasn't grounding right.
I ran a cable from the body to the tensioner bolt on the alt and it started working again.

bvolks73 · « **Reply #2 on:** April 23, 2008, 07:17:33 am »

Thanks. I'll try that.

subsonic · « **Reply #3 on:** April 23, 2008, 08:33:20 am »

There is a very small wire that connects on the back of the alt with a single female spade connector. If it breaks, the alt will not charge, the batt light will not come on, and your batt will run down. Mine has let go twice.

jimfoo · « **Reply #4 on:** April 23, 2008, 10:42:30 am »

Not sure about VW's but on most other cars if the batt light burns out, the alt won't charge either as that's where the power in the white wire comes from.

Vincent Waldon · « **Reply #5 on:** April 23, 2008, 11:00:26 am »

Quote from: "jimfoo"

Not sure about VW's but on most other cars if the batt light burns out, the alt won't charge either as that's where the power in the white wire comes from.

True dat, for VWs as well.

No light... no excitation... no output... no charging.

bvolks73 · « **Reply #6 on:** April 23, 2008, 01:00:19 pm »

Quote from: "Vincent Waldon"

Quote from: "jimfoo"
Not sure about VW's but on most other cars if the batt light burns out, the alt won't charge either as that's where the power in the white wire comes from.

True dat, for VWs as well.

No light... no excitation... no output... no charging.

I ran a wire directly from the battery to that connection and it did nothing so I'm assuming that's not the problem.

burn_your_money · « **Reply #7 on:** April 23, 2008, 03:05:26 pm »

Take off the alternator and bring it to crappy tire. They will test if for free

bvolks73 · « **Reply #8 on:** May 06, 2008, 09:51:56 pm »

I found the problem. When I pulled the brush holder/ regulator everything was really rusty. Cleaned up all the rust and put it back together and it works great.