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http://www.rowand.net/Shop/Tech/images/AlternatorWiringOverview-1974to1985Buick_small.jpg[/img]
This is the best and simplest drawing around that shows how GM wired their alternators. GM did not run a wire from pin #2 directly to the alternator "Battery" post and I'm guessing you wish to achieved the same results they have. The loop up to the junction block and back provides the voltage sensing needed to regulate the voltage properly. MAD Electrical does a much better job of explaining this.
Voltage Sensing A diode from pin #2 to "Bat" is claimed to achieve this, but I've tried a couple of diodes with no success.
The resistor shown is actually a resistance wire that goes from the firewall plug to the ignition switch. I'm not sure, but that may be why they they have it on its own switch connection. You can use the one single switch connection(IGN) for the light and put a 10 ohm resistor in parallel, across the light. I have seen some cases where they worked without the resistor, but get a 10 ohm 10 W wire wound resistor and you'll be happy.
If you're interested, note the similarities in this wiring.
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http://www.rowand.net/Shop/Tech/images/AlternatorWiringOverview-1963to1972Buick_small.jpg[/img]
