alternator light wire

2,408 posts · joined Feb 2003 · 20 Jun 2003, 12:10 pm

#58640

Ive installed a new alternator in my 69 beetle, and its not charging the battery.

Ive been checking all the wiring and making sure all the wires are meant to go where they are supposed to, when i noticed 1)( the key is turned and the car is not iding/running) when i moved the generator light wire under the dash, the light turned on (the light had not been working for some time) like its supposed to normally (from this i gather that the lightbulb is working) but then i find 2) the alternator light wire is ummm... cooked and the plastic melted... this has caused me to move the wire again and the light will not come on no matter what i try.

Ive put an ohmmeter to the light connection and find that there is no reading. I try it for the oil light and blinkers and get a reading. From this I gather that the wire itself is cooked.

This may seem like a stupid question, but would this cooked and melted wire be causing a short somewhere and therefore somehow be the reason that the alternator is not charging the battery?

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 · 20 Jun 2003, 1:09 pm

#58653

sounds like it's possible you have hooked up something wrong and cooked the regulator.

as a simple check, do the following.

run a wire straight from the battery, through a light bulb and out the other side. from there continue the wire to the warning light wire on the alternator.

Now with that wire connected, and the engine off, the light should be on. The power from that light continues to the alternator regulator and basically excites part of it.

Now start the engine, the light should turn off. The voltage in the system should go up to around 14V.

If you fail that test, you need a new regulator. The internal regulator in the alternator is a little tricky to replace (I found it doesn't quite fit and needs slight modification) but can be done. The last alternator regulator I bought cost me about $40 from a bosch parts stockist.

Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

Starbug rustbag

2,408 posts · joined Feb 2003 · 20 Jun 2003, 3:13 pm

#58686

if the wire was melted before i put in the new alternator, it would have stuffed the regulator in the new alternator as soon as i started it right?? 'cos ive just noticed on the old external regulator that some of it is fried and fused.

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 · 20 Jun 2003, 5:28 pm

#58700

possibly. do the check I described and you will find out.

Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.