Alt light on

Bizarre Moderator The artist formerly known as blue74l

12,785 posts · joined Aug 2002 · 10 Sep 2011, 12:34 pm

#861216

My mate put a rebuilt alternator on and it "looks" like all the wires went back in the right spots.

But the Alt light glows ALL the time

I told him he should only have the dizzy wire to the negative of the coil - but there is a 2nd green & white stripe wire there.

Whatever - ALL the wires disconnected from the dizzy and the light is still on

It is an internal reg alt.
Had the brushes (or slip rings or whatever) done.
It only has the 3 wires so I cant see where it is wrong.

He hasnt tried starting it yet

Any ideas??

Futue te ipsum!!!

SebastienPeek Custom Title Time!

1,657 posts · joined May 2011 · 10 Sep 2011, 3:37 pm

#861245

Usually if the alternator light is always on, it means it is wired up wrong...

I'm assuming that he has bypassed the external regulator (if there ever was one)?
I don't think the distributor would have anything to do with the alternator light always staying on, it is definitely the wiring of the alternator itself.
Make sure that all the wires that are attaching to the alternator are in the right order and clean the contacts as well if need be.

Also, you say he hasn't started the car. The alternator light only goes off when you actually start the engine. It glows when the ignition is live, and then turns off as soon as the engine kicks in. If the alternator light is still on while the engine is running, then it is definitely a wiring issue.

🙂

The sold one, '73 VW 1303 - Zelda
The project, '74 VW 1303 - Gretl

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 10 Sep 2011, 3:44 pm

#861246

You mean the light is staying on with the key off?

If its a 72 or later bug there will be a grey/green wire to the coil neg which is just the diagnosis wire up to the plug which does nothing, but other option is a tach wire? you know if its got a tach installed?

only 3 wires? is that to the alternator?
should only be 2
big B+ and the warning light wire.

Anthiron The Baja Rejuvenation Begins

4,936 posts · joined Oct 2003 · 10 Sep 2011, 4:49 pm

#861259

Dont externally regulated Alts have 3 wires and internally regulated Alts have 2 wires?

Are u sure its internally regulated?

62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom

Anthiron The Baja Rejuvenation Begins

4,936 posts · joined Oct 2003 · 10 Sep 2011, 4:51 pm

#861260

Alternator Wiring

Earlier alternators used an external regulator and therefore had more external wires connecting to it. Later alternators had less wiring.

Externally Regulated

Alternators requiring an external regulator have a B+ terminal and a triple terminal in the center top for three other wires that should be wired into a socket made for this triple terminal.

The triple connector has a red (D+), brown (D-) and green (DF) wire that connect to the voltage regulator. The regulator has a forth blue wire (61) that connect to the alternator warning light.

A single larger red wire with a ring terminal should connect to the B+ terminal on the alternator.

Internally Regulated

Large red wire connects the battery to the B+ terminal

blue wire in the main harness goes to the D+ terminal. This wire connects to the alternator idiot light and must be connected in order for the alternator to charge.

External Regulated to Internally Regulated Alternator

The larger red wire goes to the B+ terminal

The green wire should be connected to the blue (61) wire and the green wire can be connected to the D+ terminal. The voltage regulator should be disconnected and can be removed if you like.

taken from
http://vw.zenseeker.net/Alternator.htm

62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom

Bizarre Moderator The artist formerly known as blue74l

12,785 posts · joined Aug 2002 · 10 Sep 2011, 5:31 pm

#861267

It is a 1975 L bug

It (and mine) has 3 wires
2 to the post (a larger and small)
Both of these have the eyelet so have to go there

1 to the spade connector

Futue te ipsum!!!

SebastienPeek Custom Title Time!

1,657 posts · joined May 2011 · 10 Sep 2011, 5:58 pm

#861270

Yep, mine is an L bug too, andi have the exact same setup!

But, under the seat, I had an external regulator that needed to be bypassed.
However, I'm assuming you had a period specific engine and the alternator was already installed as after 74 they all came with alternators and thus, no external regulator.

Like I said before, the light should glow if the ignition is on and then once the engine starts, the light should go off.
🙂

The sold one, '73 VW 1303 - Zelda
The project, '74 VW 1303 - Gretl

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 11 Sep 2011, 11:58 am

#861385

Bizarre wrote:It is a 1975 L bug

It (and mine) has 3 wires
2 to the post (a larger and small)
Both of these have the eyelet so have to go there

1 to the spade connector

The small black wire to the B+ terminal does nothing same as the extra coil neg wire.
Just runs up to the computer diagnosis plug.

Bizarre Moderator The artist formerly known as blue74l

12,785 posts · joined Aug 2002 · 11 Sep 2011, 2:29 pm

#861409

so = one would have to assume the alternator has not been fully repaired??

Futue te ipsum!!!

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 11 Sep 2011, 3:34 pm

#861416

That's what I'm thinking
I'd be interested if it's actually putting out any charge.

For the light to be on with no ignition means its feeding 12 volts down the field wire which doesn't compute unless the regulator is faulty.

Bizarre Moderator The artist formerly known as blue74l

12,785 posts · joined Aug 2002 · 11 Sep 2011, 4:06 pm

#861417

any harm in turning it over??

Futue te ipsum!!!

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 11 Sep 2011, 4:41 pm

#861423

THE REGULATOR IS THE WEAK LINK IN EXTERNAL REGULATED ALTERNATORS...

replace the regulator....

[also need to check the brushes to see if they are worn out..]

if the regulator isn't working, the alternator may be putting out about 18 volts AC instead of DC...

check if headlamps go brighter when engine is revved...

AC won't charge a battery....

but 18 volts AC can burn out stuff

Lee

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---