generator testing, repair options

[kyle242gt]

I have a 1600sp from a 70 sedan; generator spins when DF is grounded and 12V applied to D+. I get no power from the generator when DF is grounded and the engine is running.

Question: does that establish that the generator is bad?

Second question - if so, has anyone had luck having one rebuilt, or should I just buy a reman ($65 lifetime warranty)?
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1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it

[Russ Wolfe]

Typically, if it motorizes, when you ground the DF, that is a sign that the generator is good. And when you ground the DF with the motor running, you should get about 20V out of it. Are you sure you have a good ground with your meter, or have it on the right range. If you have it on the 20V scale with a digital meter, it may go out of range.
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Society is like stew. If you don't keep it stirred up, you end up with a lot of scum on the top!--Edward Abbey

Gary: OK. Ima poop.

[kyle242gt]

Thanks, Russ - that was my thought too - but the testing instructions I had said zero output after polarization (and visible spinning) indicated a dead generator.

When I ground the DF, there's visible arcing, so I guess that says the field windings are drawing current?

I'm pretty confused.
_________________
1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it

[wmcclay]

Where in nor cal are you, I can recommend a few good places to test and repair. We use these for our fleet of 250+ vehicles. Wayne

[kyle242gt]

Santa Rosa - there's a couple local shops, but I'm tempted to just go to ratblasted autozone, plunk down my $65 (.065K?) and be done with it.

This stupid car has been in my possession for going on 40 days, and it's starting to piss me off. Ride or DIE!
_________________
1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it

[wmcclay]

Good luck.

[67 Florida Deluxe]

I hear there are Chinese-made ones at Wal Mart.

(OK, just kidding )


I have had a 1961 Mercedes generator rebuilt and a VW generator rebuilt, both with great success. Personally, I'd opt for having it rebuilt from a reputable shop before buying an aftermarket replacement.
_________________
-Kent (BaT "daleallen")

OG member of the '67 Posse

A few of my toys, past and present
'56 Oval, '66 KG Conv't, '67 21-Window, '67 Bug, '79 SuperVert, '55 Pre-A Continental

[Cusser]

I agree with Russ - a spinning generator, operates as a motor, is OK.
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[kyle242gt]

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

I'm stumped. Time to pull it and get it tested, I suppose.
_________________
1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it

[turtleturtle]

I would never get one at Autozone. Had some very bad experiences with them once. They gave me 2, I repeat, 2 generaters that were bad. I finally just got all my money back and got a good one from Oriellys. Not saying that is what you should do, but I don't even look at AUtozone as I pass it by going to work everyday. Been nothing but crappy parts after crappy parts.
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http://www.rankmyride.com/?page=cars/view&CID=9190

[&Dan]

Autozones are staffed by pimple zoos with only a passing knowledge of automobiles.

They're a great place to buy brake cleaner and pine tree air fresheners.

Apart from that, they are Enemies Of The People.

[weinerbug]

Sounds like a good generator. DF ground after it is running is just another test procedure. What happens if you don't ground it and just run normally and rev up. You would test at ground and DF+ to see if voltage rises.
Have you considered a bad voltage regulator?
I don't get any red light out until I hit about 1000 rpm, so it takes some rpm to note a voltage rise.

[kyle242gt]

Took it to an old timer, he tested and said it's okay. But I caught a familiar whiff of MJ about the place when I dropped it off, and he never took off his sunglasses, so his judgment is suspect.

Put it back in and tested again. With DF grounded, I get about 3V once it starts working (1500?), maxing at about 4-5V. (it's a 12V gen) My 1157 test light glows fairly well at 3000RPM, and barely barely barely glows at 1500 or so.

The brushes look okay, are making contact. Their outer faces (where the springs hit) are about 1/16" from their little cages. Pushing them seems like it might help, a bit. But I can only push one at a time. How long are new brushes? Mine are about 5/8" or so. The commutator looks fine, reasonably shiny.

They are more or less in between these two:
http://www.reluctantmechanic.com/images/vw_beetle_generator_brushes_oldnew.jpg
And they look like this in situ:
http://www.reluctantmechanic.com/images/vw_beetle_generator_top_s.jpg

Thanks for any advice.

I do not have the generator warning light connected (still have 6v bulbs up there), but since I'm only testing the gen, I don't see how the regulator or warning light would have any affect.

I did plunk down the $70 for a new one at AZ, but haven't picked it up yet... is there any point in disassembly?
_________________
1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it

[KTPhil]

Wrong or worn brushes if they are level or below the top of the square hole they mount in.

[kyle242gt]

Hooray! It's up and running.

Turns out the generator stand and case were so grimy and corroded, it wasn't grounding the generator well enough.

Cleaned things up a bit, and voila, 14.5V.

Thanks to all for the helpful advice.
_________________
1967 Type 3 Fastback, gathering parts for resto mod - "Stay on Target!"
gone but not forgotten:
1964 Type 1, sunroof, 1600sp, 4" narrow, 2.5" trans raise, pan smacker
1972 Type 3 Squareback - never did much to it