Anybody got a JPG of this? Im trying to diagnose my alternator not charging. I believe I have it traced to the firewall plug.

Also, those outer socket plug connectors, is there anywhere in Canada that I can get these, other than a similarly corroded firewall plug in a wreck? Are these same terminals used elsewhere in the car, like the interior?

Ive looked at the Haynes manual and as usual it makes no real sense. The FSM I have is for '77 passenger cars. Not much help there.

I think these are the terminals you are talking about. There are 56 series and 58 series and I believe the only difference is the mating force. I researched it a couple years ago, but forgot where I found it.

http://fmsiinc.com/terminals-oem.htm

That's awesome that you found a canadian distributor of those terminals. They have a lot of other nice stuff on that website as well. But you have to have a commercial account to place an order.

I found an alternator wire extension socket from Motormite at the local Partsource for $6 and managed to extract the two male spades I needed out of it to replace my fusible link. I installed a 16ga link and replaced the female socket in the firewall bulkhead as well.

Unfortunately I am still not charging. The ammeter needle still jumps to the right on startup, but goes back to discharge. The battery remains at 12.4V. The Haynes manual only provides a brief overview of the regulator and how it works. The 77 manual provides a detailed diagnostic section on the solid state regulator system, with electronic ignition, so I cant use the specs for my mechanical regulator system with ballast resistor. My regulator has a plastic housing.

Now I do know the alternator output wire should read battery voltage with engine off, dynamic voltage with engine on, the case needs a good ground, and the field wire should read battery voltage with key on, engine off. The regulator also requires a ground. I will check these specs and report tomorrow, but beyond that I dont know what else I should be reading at the terminals.

If I had a good diagram I might be set. Also, is there any way to "full field" the alternator to eliminate it as a problem, other than putting a load tester across the battery?

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

The only service manuals I have are '64 and '66 and the only tests they show require special test equipment.

If your ammeter is showing charge at startup, your alternator is working, so I'm inclined to suspect the voltage regulator or the wiring...especially grounds.

Unless you want to retain originality, I'd get an electronic regulator. Once the points wear on a mechanical regulator, I've never been able to adjust them to work properly. They have electronic regulators that look exactly like the original.

A quick test to see if an alternator is charging is to touch the tip of a screwdriver to the center-back of the alternator with the engine running. If it's charging, you will feel a magnetic pull.

Hmm, well the ammeter needle bounces right when the engine catches, but it's a constant drain after that. Im not sure now if the regulator is an electronic one, since the housing is plastic. I'll be sure and check that now, thanks! :D

Will that affect what my readings should be? It doesnt look like the wiring was altered to accomodate it.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Did someone connect an extra electrical load to the "wrong" side of the ammeter? Or anywhere between the amp gauge and battery positive terminal? (You know, that after market MSD ignition system you installed!!) That will cause the ammeter to show constant discharge even though the battery is not discharging.

Nope, the car is 100% bone stock, and I never got further with the MSD set than pulling the distributor and trying in vain to get the shutter wheels to fit.

I just went out one cold morning, started the car, and looked at the gauge and it was in the red rather than the black.

edit: figuratively speaking

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

A mechanical regulator should have a cover that can be removed. Depending on brand, the electronic replacement will probably look nearly identical to the original, but the back side will be encapsulated and the cover can be removed.

The wiring is identical for the electronic replacement, unless someone converted to the newer style regulator.

Thanks everyone for all your ideas. The charging system is well again. Here's what I did:

After reassembling the car after yesterday's fusible link replacement (the insulation was split) I ran some tests. Based on what I knew, I verified battery voltage at the output terminal, verified grounding of the engine block, alternator, and the regulator, and removed the regulator to clean the ground terminal. Yes it was electronic. The wire from the ballast resistor showed battery voltage at the IGN terminal, but nothing at the field terminal. Verified continuity of the wire from field terminal to alternator. Replaced the regulator with a new electronic early style regulator RIGHT off the shelf at Canadian Tire... wow. $25. Reconnected battery and started car. Needle is in the black now.

I'm not crazy about the appearance (black plastic) but it's solid state. If anyone else has some anecdotes by all means keep em coming. I found the Haynes manual to be quite inadequate and Im sure it has frustrated some of you as well.

Cheers

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

try this site: www.allpar.com/fix/alternator.html

there was some differences in what i was dealing with, but it did help, no specs though

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IS 40:31 gets me through lifes challenges.