When my 77 Bug is idling my voltmeter shows 13-14 volts. When I turn on everything EXCEPT my headlights there is a small drop. But when I turn on my headlights the volts barely read 12, and the Gen light is glowing. The headlights are 'modern' brighter lights. I don't think they're halogens.
Do I need to get an alternator with more Amps?
Shouldn;t have to upgrade unless you want to.
There's a problem in your system.
Most likely you are not grounded good somewhere.
Try Making sure the Engine/Transmission is grounded to Chassis really well, and Then Work The rest of the grounds in the electrical system one at a time using your Wiring Diagrams.
There Shouldn;t be any problem with the newer headlights ,................Even if they *were* halogens.
Remove "YOURPANTIES" to reply MUADIB®
On Wed, 3 Sep 2003 18:35:07 -0400, "Mel P." scribbled this interesting note:
No. This is not necessary. Fix the problems in your electrical system and you will fix the problem.
-- John Willis
At idle, this sounds reasonable to me. Does the light go out when you speed up the RPM's a little bit?
I would say no. My 1973 with a Bosch alternator does the same thing. When I first start up and start going, the needle on the voltmeter shows about 14 volts. After the battery gets charged up it shows a little over 12 volts. With the headlight, wipers, turn signals, and brake lights, it shows about 10 volts, and yes the generator light glow a little. I was told it only needs 9 volts showing on the voltmeter to keep it running.
Check your fan belt tension. It should deflect between 1/2 inch and 3/4 inch when you press your thumb on the middle of it. Check your battery terminal clamps and posts. Have they been cleaned lately. Get a battery acid absorption matt to place under the battery. How old is the battery? I had a 55 or so month battery die on me at about 23 months. I was sure there was nothing wrong with it and that I needed a new alternator but I was wrong. It was the battery. Actually the person to ask would be the Aircooled VW Electrical Guru Speedy Jim at
Current capability goes up with RPM, so your alternator is at its worst at idle. They are rated at much higher speeds. It's really not fair to test yours like this; you have to give it a chance and do this test at 2000-2500 RPM.
------------------------------------------------ Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA
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