Has anyone ever changed diodes on an AL82N alternator?

Jan,

Thanks guy.

Humm . . . have to pull the engine aye? What a bummer.

This is another fine mess I've gotten myself into. - Having never pulled an engine before.

But you know what? If it's really necessary I think I will do it because I have heard that the VW engine comes out fairly easily.

What do you know about alternators? Do you know where to get diodes/bridges? What can you say about after market stuff? How reliable are the various rebuilds? What's the likelihood that the diodes vs. the voltage regulator would be the problem? My thought: diodes are more likely the problem.

My original thought was to simply replace the whole lot of diodes and the voltage regulator all at once before reassembly. Now, I'm thinking that I must perform a more rigorous test of the alternator before proceeding. After all, I don't want to needlessly remove the engine.

I might even put in a new voltage regulator and give it a try. At least that way I would be able to "scope" the output. It seems I remember a time when the cars dead battery was removed and replaced with a good one for the purposes of starting. Then, the "good" battery was removed and the original discharged battery was placed back in the car and all while the motor was still running. I have read that this is a sure way to blow the diodes. I know that on a modern vehicle, this kind of failure would never be tolerated, but back the 1979 when this Super Beetle was made, they hadn't yet gotten the electronics right. I'm wondering if newer rebuilds have modern protection circuits built-in or if such a circuit can be added external to the alternator. Have you ever heard about anybody doing any of this?

Again, thanks for the postback,

- Stan Shankman

You don't need to pull the engine to get the alternator out. I did mine twice in a day, after the first rebuilt alternator turned out to be bad, I took it back & exchanged it for a new one. The hardest part for me was pulling the Weber progessive & getting the manifold to slide out of the way. At that point I wished I installed dual carbs instead of a progressive.

Jim

True.

Umm.. enough to rebuild them?

Can't help you with sources local to you, sorry

That's what I opted for last time, BOSCH was so damn expensive. Aftermarket diode bridge was less than HALF of the bosch price! Has been working flawlessly for about a year now.

Never bought a rebuilt alternator off the shelf.

The regulator is much easier to replace.. and it wouldn't hurt to try that first. Worst case is, you end up with two good regulators. Always good to have a spare.

You could perfom other maintenance to the engine too while it's out. And take a look at the engine bay, if it needs any work.

Yea I've heard of the "remove battery cables and see if the engine keeps running or dies" trick. I don't know if it's an acceptable way to troubleshoot the system though.

If you need pics of alternator diode bridge change, lemme know.. I have some, but not online yet. Email me. snipped-for-privacy@rocketmail.com

While you have teh alternator apart, replace the bearings too. They're cheap.

Jan

I just removed the proggy, left the manifold in place. Loosened the two fanshroud bolts & removed throttle wire, engine lid & hinges ! Once here, i could lift the fanshroud & jam a piece of wood under the right hand side. Loosened the four alt plate bolts with a box spanner & swearing and brought the alt & plate straight out. Took about 45 minutes, inc interruption from kids and neighbour.

James

Engine removal: 15-20 minutes...

Jan