Generator Light Stays On

[JimSP16]

Just rebuilt engine, turn on ignition, start car. Green light goes off, red light stays on while running engine or if I turn ignition on with both lights on. Red light does not flash, or otherwise fault. It just stays on. Generator and belt hooked up about 1/2 inch play in belt. Seems to idle and run fine. Can not discern what John Muir is telling me in Idiots Guide. Any help out there? Thanks in advance

Jim.

[[email protected]]

The generator light is also a warning light that your fan is not spinning. Once the fan stops spinning and blowing the cool air, meltdown is immanent. With the light always on you would not know if the belt failed and that immanent meltdown would happen.

If the car has an alternator, that lit generator light means you are not making a charge and will eventually die from lack of electricity.

If it were me I would probably check the fanbelt like you did and then drive it home to fix the problem. I have had issues at the voltage regulator and would just check all my connections there first. There are some nifty wiring diagrams in the technical section here on the samba.

Alternators and generators do not look the same. A generator is the same diameter its entire length. An alternator has a fat end by the pulley and gets skinnier towards the fan shroud.

[JimSP16]

Thank you, thank you, thank you. I just rebuilt this engine. My first complete rebuild. Haven't even been out driving it yet. Your experience saved me another rebuild.

Jim

[catahoula lou]

Like mine did recently, your generator (not alternator, I believe) brushes could get hung up within their holders, making less/no contact with the armature. With the engine off, push/GENTLY tap both down into place against armature for good contact. Easiest fix for a generator light that comes on, provided it is the cause.

Best,

Thom
_________________
1 great wife
2 Catahoula Leopard Dogs (Mahogany Star and Spartan) - RIP Lucy, Braveheart, & Dusty!
1 1959 mango green Ragtop Bug (the "Mango")
1 1958 pantina red Lowlight Ghia (the "Chili Pepper")

Still looking for:
(1) My Dad's 1955 356 (he raced it amateur-class at Riverside and other courses during 1950s),
(2) My parent's black 1955 hardtop bug (CA license plate FWC 201 or FWG 201), and
(3) My parent's agave green 1957 ragtop bug (CA license plate LFK 734).

[scottyrocks]

I have been working on my car's stumbling for quite some time and believe I have finally fixed it last night.

When I started the car for a test drive, the generator light was on full blast and would not go out. Prior to last night, the gen light would go out when it was supposed to, right after startup.

I have already checked the voltage at the battery with the car off (6.29v) and while revving the engine (6.12v) and there is no change when I rev it which says to me that now either the generator isn't working or there is a wiring or ground problem.

I have thus far been working off of these two pages,

https://www.thesamba.com/vw/forum/archive/index.php/o-t--t-418512--.html

http://www.vw-resource.com/generator.html

as they contain what looks like the most relevant-to-my-problem information.

I also performed the 'push the brushes against the armature' test while the engine was running. No change at 6.12v, so I guess the brushes are okay.

Some questions:

Where is the generator grounded to the engine or frame? The generator tower sits on paper gaskets. The two red wires to the vreg are positive, afaik. What about the green wire to the other terminal on the vreg?

I also want to do the 'check the maximum voltage' test. Rob and Dave talk about the D+ and DF terminals on the vreg.


<< Check the Maximum Voltage of the Generator -

Disconnect the generator from the regulator (both the DF and D+ wires).

Use a jumper lead to connect DF to the generator frame (grounding the DF connection).

Now start the engine and test the voltage between D+ and the generator frame.

The voltage should increase with rpm up to about 35 volts (20 volts or so for the 6-volt generator).

If the generator passes this test, it's working okay. >>


Which one is DF and which one is D+? I see no markings, and the wiring diagram shows nothing of this. If I'm going to do the tests they outline, I need to know which is which. Is the D+ the one with more wires attached to it (the one on the right)?

I am thinking right now that the problem is simply a loose connection but I can't find it. I also don't see how the generator is grounded as it is isolated from the engine by paper gaskets, but there is nothing different now than when the gen light went out as it should.

Other than me removing and then reinstalling the top of the carburetor, nothing has changed since it ran with the gen light out.

I would very much appreciate any ideas.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[flyboy161]

See the illustrations below

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http://www.thesamba.com/vw/forum/viewtopic.php?t=603879

The 1964...Diamond in the rough
http://www.thesamba.com/vw/forum/viewtopic.php?t=612776

My 1958 Morocco Bug-
http://www.thesamba.com/vw/forum/viewtopic.php?t=611483

[scottyrocks]

Thank you for that. It was what I suspected but wanted to be sure.

While I was waiting, I decided to attempt to ground the generator so that I could either conform or eliminate ground as the issue. So I fabbed this:

Started car, gen light went out. Meter rose to 6.86v when I revved it.

It's not 7.0-7.2v, and it still doesn't explain why yesterday the generator was suddenly not grounded, but it works.

Hopefully this will be of some help to others.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[scottyrocks]

So it's been a couple of weeks since the above post. Since then I have found out that my little ground wire actually does nothing that isn't done by the generator being grounded via the stand and its mounting bolts. The installation of the ground wire and the light going out were coincidence, which is focking weird. But my issue is elsewhere.

Just now I attempted to push the magnets in a little closer to the armature by tapping. I put a screwdriver on the brackets that hold the magnets in and tapped with a hammer. Started the car and the light stayed on.

According to the testing procedures on this page:

http://www.nls.net/mp/volks/htm/gen.htm

the brushes are either not the problem, or they are so worn out that pushing on them does nothing, although I don't think this is the case because the generator was charging one day a weekend or two ago, and then just stopped charging.

I'm not sure because all it says is 'If the brushes check OK, do this test.' Does 'okay' mean that when you push them in you get a reading that says they are charging? If so, they are worn out and not okay. Or does it mean that you don't get a reading that says they are charging, therefore the problem is elsewhere which means the brushes are okay? I think I just answered my own question.

Next weekend (I am where the car is only on the weekends) I will perform the next test on that page, as well as what are on pp. E-2 in the Electrical System chapter in the Bentley manual.

Depending on the results of that test I will either polarize the generator (not likely the cause as it was charging a week or so ago). If that doesn't do it I'll replace the brushes. If that doesn't solve the problem, cleanup the copper of the armature. If that doesn't solve it, get the generator rebuilt.

Does this sound like a logical game plan?

Would a failed voltage regulator cause a no-charge condition?
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'

[Cusser]

[Airstream65]

I just had same problem last week. I tested the generator and then regulator, regulator was bad. I replaced it with a new Bosch...problem solved!

[scottyrocks]

I hooked everything up for a generator test as per Bentley. Then the car wouldn't fire.

At that point I pulled the generator and will be bringing it in to a local automotive electric shop on Monday for a commutator cleaning and new brushes.

While poking around I noticed that the wire from the generator to the vreg D+ has a break in the sheath right where it exits the generator and curves up to the vreg. The break was touching the generator housing. Positive wire on negative ground (if the casing is ground) is probably not a good thing. So I'll have them do the wiring, as well, and I whatever else might be needed.
_________________
“If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch'