Switching from External to Internal regulator..any tips?

[rennch]

Anyone have a how-to on the wiring for this? I'm buying a new alternator as my last bastion of hope for my alternator gremlins. The car is a 72T with a 79 3.0 Engine. Thanks!

[304065]

Why? If you do this and it works then the answer was a hell of a lot more simple than doing it. Does that make sense?

There are a couple dozen threads in the archives on how to convert over, but I wouldn't recommend it.

It's been a while, what have you isolated the problem to?

[rennch]

Wait...you WOULDN'T recommend going to an internal? I thought that was the newer, better way?

It looks like I might have a faulty diode in the alternator.

[304065]

Nah, don't do the internal unless you really want to.

The later alternator is heavier.

It requires a different fan shroud, like a 930. . .4R or 7R or something like that, I don't remember (although I will look on my shroud and tell you this weekend if you want).

Most of all it puts the regualator in close proximity to the engine case. This summer at Gingerman I found that the VR would overheat and shut down, which would cause the low voltage light to come on. Except there's no way to tell whether the VR has overheated or the fan belt has come loose. . .which means shutting off the engine immediately. At least with the external VR it's somewhat away from the engine heat over on the console, and it's easier to swap out for diagnosis purposes.

Anyway, whatever trouble you are having, you are having regardless of whether the alternator is internal or external, e.g., if you are sure you have a bad diode, that's no reason to update to the internal reg. It's more work and more money.

I'm actually going to convert back to a 55 amp motorola external reg'd this spring FWIW.

[rennch]

John,

You're my hero. You've been very helpful during this whole process. If, for some reason, this new alternator *doesn't* fix the problem, I'm flying you out to Colorado to help me.

Thanks.

[chibone_914]

MTO you have mail.

[scottb]

Why not just have the alternator rebuilt and the diode replaced? Am I missing something here?

[rennch]

I'm getting cost on a new Bosch alternator...that's why. It's cheaper than having it rebuilt.

[scottb]

I had mine rebuilt for $89.

[rennch]

I haven't found a place anywhere around here that would do it for less than $175.

Nevertheless...I'm not having it rebuilt. I have had so many problems with my alternator that it's worth the extra 50 bucks to get a new one with a 2 year warranty. Thanks though.

[pwd72s]

Here's a link to an earlier thread...If I could find it by doing a search, anyone can. In this thread, Warren posts factory service bulletins on the swap I printed 'em out...you may want to do the same. Me? When the time comes, I'm hoping to go with a successful rebuild...


Correct alternator Output


Another link..this firm rebuilds electronics for independent shops in the Southern Cal area...

http://www.systemsc.com/


Finally, IF your '72 alternator is rebuildable, I might be interested in it as a spare...but it might not be if a previous shop messed it up?

[rennch]

I have two alternators, one is a Marchal, one is a Bosch. The Marchal definitely needs a rebuilt...not sure about the Bosch currently in the car. This is all part of the troubleshooting process.