those old delcotrons are pretty simple the two prong plug should have a red wire and either a brown or a white wire the red wire should have 12 volts or better all the time the white or brown wire should have 12 volts or better with the ignition on. if the red wire does not have power check the fusible link down by the starter or you can cut it about 6 inches down in the harness and put a ring terminal on it and connect it right to the batt terminal on the alternator if the brown or white wire does not have power check the ignition switch
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