Annoying Generator Light

Hi,

Since I've had my Bug, the generator light has been steady on. The
wiring harness is a nightmare and since the battery has been getting
charged....simpler just to not get involved. It's always made me
nervous though, and sure enough I recently had the belt come off due
to an under-tight alternator pulley nut. The engine overheated before
I realized anything was wrong, though thankfully it was just around
town and not on the highway where some serious damage would have been
done.

Realizing the error of my ways, I set out to fix that damn light. The
car (a '74 standard) has had an alternator conversion, but whoever did
it used some creative wiring. At the alternator, there is a large red/
white [1] AND a mysterious black wire [2] connected to the B+
terminal, and a mysterious red wire [3] connected to the D+ terminal.
I tried connecting the hacked-off remains of the green wire to the
alternator, but it did nothing.

Today I started monkeying with it some more and only after finding
Speedy Jim's pages on the subject (highly informative, kudos to Jim)
did things finally make sense. So, I spliced the blue and green
wires from the regulator together and replaced the mysterious red wire
on the D+ terminal with the green wire. Unfortunately, the light
STILL doesn't work as it should.

I am fairly certain it is wired correctly, and the light does come on
with the key, but stays on while the engine is running (however, its
brightness is now directly related to engine speed, whereas before it
was inversely related). I believe the problem is that with ignition
on and engine not running, the voltage at the green wire is a measly
9-10 volts. The D+ terminal puts out 14-15 volts when running. I
figure the wiring on the ignition side of the light is just so shoddy
that there is enough "backflow" though the warning light to keep it
on. The voltage at the red wire (that was previously connected to D+)
is more like 11-12 volts, still not equal to the battery voltage but
closer. Now that I'm thinking about it, I'm not even sure how the
warning light was working before, as the blue wire wasn't connected to
anything before I started...

So, anyway, does anybody think I have a chance at getting this working
without rewiring the entire car? I fully intend to do that, and
soon, but it would be nice to have the light working in the
meanwhile. Also, I figure it probably isn't good for the alternator
to be seeing that low of a voltage at the D+ terminal. Would I be
better off just using the mysterious red wire until I rewire the whole
damn thing and put these issues behind me?

Thanks,
Harry


[1] The red/white wire appears to be correctly spliced into the
battery and fusebox.
[2] I have no clue where this goes.
[3] No clue where this goes either, though it does not appear to be
the red wire that used to go to the regulator, as that looks
undisturbed under the rear seat.

Harry Smith wrote:
> Hi,
>
> Since I've had my Bug, the generator light has been steady on. The
> wiring harness is a nightmare and since the battery has been getting
> charged....simpler just to not get involved. It's always made me
> nervous though, and sure enough I recently had the belt come off due
> to an under-tight alternator pulley nut. The engine overheated before
> I realized anything was wrong, though thankfully it was just around
> town and not on the highway where some serious damage would have been
> done.
>
> Realizing the error of my ways, I set out to fix that damn light. The
> car (a '74 standard) has had an alternator conversion, but whoever did
> it used some creative wiring. At the alternator, there is a large red/
> white [1] AND a mysterious black wire [2] connected to the B+
> terminal, and a mysterious red wire [3] connected to the D+ terminal.
> I tried connecting the hacked-off remains of the green wire to the
> alternator, but it did nothing.
>
> Today I started monkeying with it some more and only after finding
> Speedy Jim's pages on the subject (highly informative, kudos to Jim)
> did things finally make sense. So, I spliced the blue and green
> wires from the regulator together and replaced the mysterious red wire
> on the D+ terminal with the green wire. Unfortunately, the light
> STILL doesn't work as it should.
>
> I am fairly certain it is wired correctly, and the light does come on
> with the key, but stays on while the engine is running (however, its
> brightness is now directly related to engine speed, whereas before it
> was inversely related). I believe the problem is that with ignition
> on and engine not running, the voltage at the green wire is a measly
> 9-10 volts. The D+ terminal puts out 14-15 volts when running. I
> figure the wiring on the ignition side of the light is just so shoddy
> that there is enough "backflow" though the warning light to keep it
> on. The voltage at the red wire (that was previously connected to D+)
> is more like 11-12 volts, still not equal to the battery voltage but
> closer. Now that I'm thinking about it, I'm not even sure how the
> warning light was working before, as the blue wire wasn't connected to
> anything before I started...
>
> So, anyway, does anybody think I have a chance at getting this working
> without rewiring the entire car? I fully intend to do that, and
> soon, but it would be nice to have the light working in the
> meanwhile. Also, I figure it probably isn't good for the alternator
> to be seeing that low of a voltage at the D+ terminal. Would I be
> better off just using the mysterious red wire until I rewire the whole
> damn thing and put these issues behind me?
>
> Thanks,
> Harry
>
>
> [1] The red/white wire appears to be correctly spliced into the
> battery and fusebox.
> [2] I have no clue where this goes.
> [3] No clue where this goes either, though it does not appear to be
> the red wire that used to go to the regulator, as that looks
> undisturbed under the rear seat.
>


Sheeeesh! That's a lot to digest!

First, '74 came standard with an alternator (US), but it wasn't
the one in there now.

The original was a Motorola with an *external* regulator
mounted under the rear seat. The wiring looked like:
http://www.nls.net/mp/volks/schem/altreg.gif

When they "converted" yours to an alternator with *internal*
regulator, there were some extra wires. The Grn and Brw no longer
are neeeded.
But the Red wire must still be connected to D+.

The Blu wire ends under the rear seat. It must be spliced to the
skinny Red wire which went to the old regulator. That should make the
dash "GEN" light work.

The skinny Blk wire on the B+ stud was for the Diagnostic Socket.
See this article for all the gory details:
http://www.nls.net/mp/volks/htm/plug.htm

Much more on this page of my web site:
http://www.nls.net/mp/volks/htm/elec.htm


Post back with a progress report....

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.

On Mar 7, 8:32 am, Speedy Jim > wrote:
> Sheeeesh! That's a lot to digest!

I tend toward the verbose...

> First, '74 came standard with an alternator (US), but it wasn't
> the one in there now.
>
> The original was a Motorola with an *external* regulator
> mounted under the rear seat. The wiring looked like:http://www.nls.net/mp/volks/schem/altreg.gif

Huh...the blue wire must have been spliced to the small red inside the
plug...sneaky of them and unobservant of me. That does explain a few
things though.

> When they "converted" yours to an alternator with *internal*
> regulator, there were some extra wires. The Grn and Brw no longer
> are neeeded.
> But the Red wire must still be connected to D+.
>
> The Blu wire ends under the rear seat. It must be spliced to the
> skinny Red wire which went to the old regulator. That should make the
> dash "GEN" light work.

It sounds like you are telling me to just hook it back up how it was
before, but it wasn't working like that. The plug that went to the
regulator was undisturbed. The green, brown, etc. wires at the
alternator were clipped and unattached. There is a largish red wire
(maybe 12 gauge) that was hooked up to the D+ terminal.

> The skinny Blk wire on the B+ stud was for the Diagnostic Socket.
> See this article for all the gory details:http://www.nls.net/mp/volks/htm/plug.htm
>
> Much more on this page of my web site:http://www.nls.net/mp/volks/htm/elec.htm
>
> Post back with a progress report....

I've examined those diagrams closely, and I suppose I don't really
understand why my setup should be any different than what is shown in
the diagrams for a car converted from a generator. Is the warning
light wired differently in my gauge than it would in a car that had a
generator? This large red wire that was on the D+ terminal...where
"should" it be wired to? What about the small red wire from the
former site of the regulator?

In related news, I've been using wiring diagrams I found at
http://www.thesamba.com/vw/archives/info/wiringt1.php However, the
'73-up Std Beetle diagram doesn't really seem to match what I have.
Which should be the closest? I just went and looked it up by VIN and
it is in fact a '74.

Thanks,
Harry

On Mar 7, 6:35 pm, "Harry Smith" > wrote:

> In related news, I've been using wiring diagrams I found athttp://www.thesamba.com/vw/archives/info/wiringt1.php However, the
> '73-up Std Beetle diagram doesn't really seem to match what I have.
> Which should be the closest? I just went and looked it up by VIN and
> it is in fact a '74.

To avoid sounding stupid, I have seen the diagram that says "74-75",
but the diagram itself says it is for Super and La Grande Bugs... I
suppose that must be the one for me despite what it says...just my
luck that the diagram I actually need is the hardest to read.

Harry

Harry Smith wrote:

> On Mar 7, 8:32 am, Speedy Jim > wrote:
>
>> Sheeeesh! That's a lot to digest!
>
>
> I tend toward the verbose...
>
>
>> First, '74 came standard with an alternator (US), but it wasn't
>>the one in there now.
>>
>> The original was a Motorola with an *external* regulator
>>mounted under the rear seat. The wiring looked like:http://www.nls.net/mp/volks/schem/altreg.gif
>
>
> Huh...the blue wire must have been spliced to the small red inside the
> plug...sneaky of them and unobservant of me. That does explain a few
> things though.
>
>
>> When they "converted" yours to an alternator with *internal*
>>regulator, there were some extra wires. The Grn and Brw no longer
>>are neeeded.
>>But the Red wire must still be connected to D+.
>>
>>The Blu wire ends under the rear seat. It must be spliced to the
>>skinny Red wire which went to the old regulator. That should make the
>>dash "GEN" light work.
>
>
> It sounds like you are telling me to just hook it back up how it was
> before, but it wasn't working like that. The plug that went to the
> regulator was undisturbed. The green, brown, etc. wires at the
> alternator were clipped and unattached. There is a largish red wire
> (maybe 12 gauge) that was hooked up to the D+ terminal.
>
>
>>The skinny Blk wire on the B+ stud was for the Diagnostic Socket.
>>See this article for all the gory details:http://www.nls.net/mp/volks/htm/plug.htm
>>
>>Much more on this page of my web site:http://www.nls.net/mp/volks/htm/elec.htm
>>
>>Post back with a progress report....
>
>
> I've examined those diagrams closely, and I suppose I don't really
> understand why my setup should be any different than what is shown in
> the diagrams for a car converted from a generator. Is the warning
> light wired differently in my gauge than it would in a car that had a
> generator? This large red wire that was on the D+ terminal...where
> "should" it be wired to? What about the small red wire from the
> former site of the regulator?
>
> In related news, I've been using wiring diagrams I found at
> http://www.thesamba.com/vw/archives/info/wiringt1.php However, the
> '73-up Std Beetle diagram doesn't really seem to match what I have.
> Which should be the closest? I just went and looked it up by VIN and
> it is in fact a '74.
>
> Thanks,
> Harry
>

Last things first:

Download the diagram "1974-up Super Beetle only"

That will be correct for your car (they lied about the Super only).

Quote: "There is a largish red wire
(maybe 12 gauge) that was hooked up to the D+ terminal."

That's not correct. I have no idea where they got that wire from.
D+ should have the skinny Red wire that was part of the 3-prong plug
(Red, Grn, Brw) and now cut off. As you note, the skinny Red is
spliced to Blu back under the seat.

The GEN light in the speedo is the same for generator and alternator
cars.

Jim

On Mar 7, 6:53 pm, Speedy Jim > wrote:
> Last things first:
>
> Download the diagram "1974-up Super Beetle only"
>
> That will be correct for your car (they lied about the Super only).
>
> Quote: "There is a largish red wire
> (maybe 12 gauge) that was hooked up to the D+ terminal."
>
> That's not correct. I have no idea where they got that wire from.
> D+ should have the skinny Red wire that was part of the 3-prong plug
> (Red, Grn, Brw) and now cut off. As you note, the skinny Red is
> spliced to Blu back under the seat.
>
> The GEN light in the speedo is the same for generator and alternator
> cars.


Excellent...I feel like we're getting somewhere! Speedy as ever!

So really it doesn't matter if you splice the blue to the red or to
the green, as long as the other end is hooked up to D+. Except now
we're back to where we started in my first post...I've got the blue
spliced to green, green hooked up the D+, and still the light is solid
on.

Peace,
Harry

Harry Smith wrote:

> On Mar 7, 6:53 pm, Speedy Jim > wrote:
>
>> Last things first:
>>
>> Download the diagram "1974-up Super Beetle only"
>>
>> That will be correct for your car (they lied about the Super only).
>>
>> Quote: "There is a largish red wire
>> (maybe 12 gauge) that was hooked up to the D+ terminal."
>>
>> That's not correct. I have no idea where they got that wire from.
>> D+ should have the skinny Red wire that was part of the 3-prong plug
>> (Red, Grn, Brw) and now cut off. As you note, the skinny Red is
>> spliced to Blu back under the seat.
>>
>> The GEN light in the speedo is the same for generator and alternator
>>cars.
>
>
>
> Excellent...I feel like we're getting somewhere! Speedy as ever!
>
> So really it doesn't matter if you splice the blue to the red or to
> the green, as long as the other end is hooked up to D+. Except now
> we're back to where we started in my first post...I've got the blue
> spliced to green, green hooked up the D+, and still the light is solid
> on.
>
> Peace,
> Harry
>

HaHa. I missed the humor of the situation.

Try this:
Ground the Blu wire with key On. (Just the Blu wire end,
not spliced to anything.) The GEN light should come on.

If that works, splice a long hunk of loose wire to the Blu
end and connect other end to D+.
Light should be On and, if you measure, voltage at D+ should be
nearly Zero.

Jim

On Mar 7, 7:38 pm, Speedy Jim > wrote:
> HaHa. I missed the humor of the situation.

It takes special people to find humor in electrical gremlins...

> Try this:
> Ground the Blu wire with key On. (Just the Blu wire end,
> not spliced to anything.) The GEN light should come on.

Tried that when I was messing around under the rear seat. The GEN
light comes on when the blue wire is grounded, goes off when it is
not.

> If that works, splice a long hunk of loose wire to the Blu
> end and connect other end to D+.
> Light should be On and, if you measure, voltage at D+ should be
> nearly Zero.

That would be good to try, though I did check the green wire for
continuity before I spliced the blue wire to it. I'm not sure exactly
what you mean by the last part...are you saying with the generator
light properly hooked up to D+, with the key on and engine off, there
should be nearly zero potential between D+ and ground? That would
make sense as that is the light's path to ground...but the problem
isn't getting the light to come on, but making it go off when it
should...hmm...

Well, looks like I've got something to do tomorrow. Thanks for all
the help Jim, you are an asset to the group. I'll be back when I've
got more to tell...

Peace,
Harry

"Harry Smith" > wrote in message
ps.com...
>. Thanks for all
> the help Jim, you are an asset to the group.

indeed.

On Mar 7, 7:38 pm, Speedy Jim > wrote:
> Try this:
> Ground the Blu wire with key On. (Just the Blu wire end,
> not spliced to anything.) The GEN light should come on.
>
> If that works, splice a long hunk of loose wire to the Blu
> end and connect other end to D+.
> Light should be On and, if you measure, voltage at D+ should be
> nearly Zero.

Jim,

Okay, I've finally gotten back to this problem. My tinkering was
rudely interupted by a burned out igniton condensor.

I got some reading with my multimeter. With key on, engine off:

D+ to ground: 1.17V
B+ to ground: 10.5V
Gen Light terminal to grnd: 1.2V
and for comparison...
Speedo backlight to grnd: 9.8V

With engine running at low idle:

D+ to ground: 13.3V
B+ to ground: 11.8V
Gen Light terminal to grnd: 13.3V
and for comparison...
Speedo backlight to grnd: 11.2V

At a low idle (such as with a cold engine) the gen light is very dim,
barely on. At a fast idle or while driving the gen light is bright.
The voltage at B+ goes up some at higher RPMs, but I've not seen it
get much above 12.5V any time I've checked. I'm frankly amazed the
battery gets charged at all with readings this low, but I've been
driving it for three months now and no problems. Maybe you'll be
able to read more into this...

Thanks,
Harry