VWDiesel.net The IDI, TDI, and mTDI source.

General Information => Troubleshooting => Topic started by: bvolks73 on April 22, 2008, 07:48:54 pm

Title: Not charging, no battery light
Post by: bvolks73 on April 22, 2008, 07:48:54 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?

Title: Not charging, no battery light
Post by: truckinwagen on April 22, 2008, 08:03:24 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.

Title: Not charging, no battery light
Post by: bvolks73 on April 23, 2008, 04:17:33 am

Thanks. I'll try that.

Title: Not charging, no battery light
Post by: subsonic on April 23, 2008, 05:33:20 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.

Title: Not charging, no battery light
Post by: jimfoo on April 23, 2008, 07:42:30 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.

Title: Not charging, no battery light
Post by: Vincent Waldon on April 23, 2008, 08:00:26 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.

Title: Not charging, no battery light
Post by: bvolks73 on April 23, 2008, 10:00:19 am

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.

Title: Not charging, no battery light
Post by: burn_your_money on April 23, 2008, 12:05:26 pm

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

Title: Not charging, no battery light
Post by: bvolks73 on May 06, 2008, 06:51:56 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.