78 SuperBeetle Headlight problem

I've owned this 78 SuperBeetle Convertible for over a year now, been
doing some minor work on it (mostly interior) to fix it up. As a
machine it has always held up pretty well, except for an odd slow
drain on the battery. I've never quite put my finger on the reason for
the drain, one of the first things I did was replace the battery but
the problem still persists, and I've been mildly scared of what I'll
find if I start looking at the electrical system (it looks like a
couple of owners back had some speaker/radio system installed an
uninstalled multiple times. A bit sloppily). But the drain has never
really bothered my, I've always kind of brushed it aside, bought
something to charge the battery and went on.

But recently, my headlights will decide to turn themselves on and off
at will. It's not the switch, and every other light on the car works
perfectly, brakes, turn signals, light behind the speedometer,
everything is fine and constantly lit, except for the headlights.
Which is a bit of a problem when I'm driving at night, for reasons I
shouldn't need to explain.

Well, I'm not really sure what the problem is. I don't have too much
experience with electrical systems; could the problems be related? The
only thing that came to my mind is a short, but then again, I don't
know too much about the electrical system, and where would the short
likely exist?

Any insight and possible answers/solutions are greatly appreciated.

Starr749 wrote:

> I've owned this 78 SuperBeetle Convertible for over a year now, been
> doing some minor work on it (mostly interior) to fix it up. As a
> machine it has always held up pretty well, except for an odd slow
> drain on the battery. I've never quite put my finger on the reason for
> the drain, one of the first things I did was replace the battery but
> the problem still persists, and I've been mildly scared of what I'll
> find if I start looking at the electrical system (it looks like a
> couple of owners back had some speaker/radio system installed an
> uninstalled multiple times. A bit sloppily). But the drain has never
> really bothered my, I've always kind of brushed it aside, bought
> something to charge the battery and went on.
>
> But recently, my headlights will decide to turn themselves on and off
> at will. It's not the switch, and every other light on the car works
> perfectly, brakes, turn signals, light behind the speedometer,
> everything is fine and constantly lit, except for the headlights.
> Which is a bit of a problem when I'm driving at night, for reasons I
> shouldn't need to explain.
>
> Well, I'm not really sure what the problem is. I don't have too much
> experience with electrical systems; could the problems be related? The
> only thing that came to my mind is a short, but then again, I don't
> know too much about the electrical system, and where would the short
> likely exist?
>
> Any insight and possible answers/solutions are greatly appreciated.
>

I take it you mean the lights go Off while driving, not that
they mysteriously turn themselves On.

The headlights are wired thru the Ignition switch and the Ignition
switch is a frequent cause of many woes.
The switch wiring looks like:
http://www.nls.net/mp/volks/schem/Ign_Plug.gif
The Blk/Yell wire is the Headlight circuit.

If you have a voltmeter (or a 12V test lamp) connect
from chassis to the Blk/Yell and see if voltage drops out
when the lights go off.

As for the mystery drain (likely unrelated), go to this
page of my web site:
http://www.nls.net/mp/volks/htm/elec.htm
and look for: "How to test for excessive "drain" on the battery."

Speedy Jim
http://www.nls.net/mp/volks/

"I have no use for a car which has more spark plugs than a cow has teats!"
Henry Ford, when advised that Chevrolet was introducing a 6-cylinder engine.