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Hi guys,

I have a 68 coupe with a 289 that was in storage for a while. I want to drive it more often, so decided to replace the alternator, battery and voltage reg. I guess I should heed the advice "don't touch a running system." ;)

I replaced all. I hooked up the new alternator the same as the old one. Voltage reg can only plug in one way and battery is hooked up right way. ;) Checked connections for continuity, all looks good.

Before starting the engine, the battery has around 12.5v. After starting, it slowly goes down and isn't charging. The back end of the alternator gets very hot (I only run it for 10 seconds or so) and the one of the wires is very hot.

I assume maybe I hooked up the alternator wrong, but I used the old one as a model. They are the same brand, model alternator, the parts shop tested it and it was OK.

The battery/field wires are fine, since they only go one way with the plastic/rubber holders. The stator was connected to ground (which T's and goes to ground by the voltage reg. and also grounds there). Is this hooked up wrong? Should stator not be hooked but that wire to ground instead? Anything else I should check?

Thanks.

Justin
 

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Here's a link to a complete schematic. I suggest you get a volt meter and confirm the connections again.
Schematics

I make my living chasing stuff like this and I can't tell you how many times I said "it's hooked up right!".

Well guess what...
 

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Stator is never hooked to ground! Jeez! Your alternator is probably fried now.

You probably mis-read the posts on the back of the alternator, as there is a ground post there that T's off to the block. All of the posts should be clearly labeled as I, B, S, F, and GND.
 

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Discussion Starter #5
I fixed the problem, it is hooked to ground now. Works fine and just to be sure, took it to get tested at the parts store.

I swear to you though, the old alternator was hooked up that way. The 2 ground terminals are rusty as all heck and the stator terminal was disturbed as I removed that 2 wires from it. I can't explain it.

In any case, it is all fixed now. Thanks guys. :)

Justin
 
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