Amp meter pegs all the way right

[Diseazd]

I just fired up the new engine in my 71. The amp meter pegs all the way right a nd the alternator heats up. I changed the voltage regulator.....same result. Any ideas where to go next? Guy

[Zforce]

How long was the battery out of the car ? How long did it take for the engine to light off ? Maybe it's just dead and needs a charge.

[SteveJ]

I responded to your PM, but just to share with everybody else...

My first thought would be that the battery is undercharged. Think of an ammeter as a flow gauge. Not only is it telling you the volume of electrons flowing, it's telling you the direction of flow. Positive is toward the battery, and negative is away from the battery. I looked through the diagnostics in the EE section of the 72 FSM. It confirms this as one possibility.

I kept looking through the FSM and noticed something on the VR diagnostics, too, on EE-26. Excessive output could be from

1. A broken neutral (white) wire.

2. A bad VR

3. Poor grounding of the alternator.

4. A broken ground wire.

If you have a multimeter, you can check continuity of the wires and grounds (1, 3, & 4).

[Diseazd]

The car hasn't had a battery in 32 years........replaced the new voltage regulator.....didn't help. Put an old alternator in....works! Why would a brand new rebuilt alternator be defective?

[5thhorsemann]

Could be a full feilding condition, check the output at the alt, and again at the batt.

[steve91tt]

You could try pulling fuses and see if the current draw changes.

[SteveJ]

I talked to Guy. The alternator in question was rebuilt. He swapped in another alternator, and it worked fine. I guess that someone did a less-than-stellar job of rebuilding the alternator, probably not getting the field wire hooked up right.

[Zforce]

The car hasn't had a battery in 32 years........replaced the new voltage regulator.....didn't help. Put an old alternator in....works! Why would a brand new rebuilt alternator be defective?

I replaced my alternator 3 times before I got a good one, rebuilt anything is junk. You are better off with an original unit from a salvage yard.

[Diseazd]

Right Gforce......2nd time it's happened to me.

[SteveJ]

I replaced my alternator 3 times before I got a good one, rebuilt anything is junk. You are better off with an original unit from a salvage yard.

There are still shops that will properly rebuild alternators instead of sending them off to who-knows-where to have them rebuilt. It costs more, but you get what you pay for. Anyway, the trick is finding those shops.

[Zforce]

There are still shops that will properly rebuild alternators instead of sending them off to who-knows-where to have them rebuilt. It costs more, but you get what you pay for. Anyway, the trick is finding those shops.

Yeah that's true, back in the day there was an auto electric shop on every corner.

[chaztg]

get your electronic parts rebuilt at a local shop who is able to do this type of job. I've had the same thing happen to me with the "rebuilt" junk that the Auto Zones, O'Reillys and other purveyors of Malaysian and Chinese reman-u-f**ked up parts have in stock. A trusted mechanic long ago advised me about the lack of quality control in these parts markets and to go US or Japanese built items whenever possible.