Ok, what did I fry?

Dumb, dumb dumb. Not paying attention.

Hooked up new battery in reverse. I have a 1974 Super, which has an alternator.

After about 5 seconds, electrical tape that I had put on the terminals started melting/smoking. I immediately pulled the terminals off the battery.

Cussed a bit, and let things cool off.

Hooked battery up correctly. Now the generator light has a slight glow, no matter what. Gets brighter when I turn electrical things on, or brake lights come on.

Is there a voltage regulator somewhere that I fried and need to replace? The fuses seem Ok. What needs checking?

Thanks, Lynn (feeling STOOPID)

1974 Super
Reply to
Lynn Martin
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Dear Fried:

It could have baked the Alternator; a huge current flows back into the alternator diodes and may have ruined some/all of them.

If you're interested, the internal diagram is on my website: " Internal wiring of Motorola Alternator w/ external regulator."

In general, '74 had an external regulator, mounted under the back seat. But I kind of doubt it would have been affected.

It might be interesting to measure the battery voltage while running. Does the GEN light come on bright when the key is first turned to ON?

Speedy Jim

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Reply to
Speedy Jim

This was funny to me!!! haha!

Just went and tested it.

I unhooked the positive terminal on the battery. I took out all the fuses. I put them back in (8 white in 1-8 slots, and 4 red in 8-12 slots). The blinkers were not working before I removed and reinserted the fuses. Then they worked after reinsertion. Strange. Anyhow.

Reconnected battery positive. Generator light glows, about a medium intensity without any key inserted in the ignition. Insert key, turn, and engine starts right up. Generator light goes out and things are fine. I register 13.1 volts into the battery while engine runs.

I ran it for 15 minutes. Everything appeared normal. Lights, blinkers, taillights, all worked. No oil or generator lights came on. Normal.

I turned the engine off, and the generator light/glow comes back on! Battery Registers 12.6 volts with engine off.

I disconnected the positive lead again so I would not run down the battery.

WTF is going on?

Lynn

Reply to
Lynn Martin

Sounds like 1 diode inside the Alt shorted out from the huge current surge.

It will charge the battery like this (kinda) for a while, but I would be putting away pennies in the piggy bank.

Speedy Jim

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Reply to
Speedy Jim

"Lynn Martin" wrote in message news:VGtie.182$% snipped-for-privacy@bignews5.bellsouth.net... | Dumb, dumb dumb. Not paying attention. | | Hooked up new battery in reverse. I have a 1974 Super, which has an | alternator. | | After about 5 seconds, electrical tape that I had put on the terminals | started melting/smoking. I immediately pulled the terminals off the | battery. | | Cussed a bit, and let things cool off. | | Hooked battery up correctly. Now the generator light has a slight glow, no | matter what. Gets brighter when I turn electrical things on, or brake | lights come on. | | Is there a voltage regulator somewhere that I fried and need to replace? | The fuses seem Ok. What needs checking? | | Thanks, | Lynn (feeling STOOPID) | 1974 Super

There's a blue wire from the alternator light to the connector on the alternator. Check it for voltage. When you find that it's less than the battery voltage (which is what's on the other side of the bulb and whose difference is lighting the lamp) you'll want to switch to the AC function of your meter where a blown diode will give you a six to nine volt reading or so. Zero if the diodes are good. I just went through this drill, and after visiting my local alternator/starter repair shop today, they had no rebuild parts for that particular alternator, but they did have new or rebuilt (don't remember) for about $132. I've elected to install my spare alternator, after I have it tested. Which leads me to the question I was going to ask today. If I can't get the rebuild parts (diodes in particular) where are the parts available from? They tell me that there's a Bosch unit with the same connection scheme, how interchangeable is it?

Oh, and Speedy Jim, thanks for the schematic pointed out in an earlier post, it's most helpful!

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Reply to
carl mciver

GOOGLE: Alternator diodes

Also, you may be able to get parts thru a marine electrical repair shop.

Electronics parts houses and surplus places carry them if you know what you're looking for.

Speedy Jim

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Reply to
Speedy Jim
13.1 is too low. Your looking for just over 14V in a healthy alternator.

Raymond T. Lowe

-- E-mail=fullname,no >

Reply to
Raymond Lowe

| > Oh, and Speedy Jim, thanks for the schematic pointed out in an earlier | > post, it's most helpful!

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| >

| | GOOGLE: Alternator diodes | | Also, you may be able to get parts thru a marine electrical | repair shop. | | Electronics parts houses and surplus places carry them | if you know what you're looking for. | | Speedy Jim |

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So, you're saying that the diodes are just plain old industrial diodes and not special packaging for the application? That would be sweet, but I just gave away most if not all of my electronics parts stash. I knew this would happen, dammit! Never fails. Oh well, I never had exactly what I needed anyway.

Reply to
carl mciver

actually if you refine your search a bit you can find specific parts.

When this started being a point of discussion I found a handful of VW specific alternator parts available online...................right stuff for both Motorolla version and the Bosch unit.

Remove "YOURPANTIES" to reply

MUADIB®

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one small step for man,..... One giant leap for attorneys.

Reply to
MUADIB®

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