I recently purchased an alternator for my March Pulley setup to use the turnbuckle instead of using my stock 1986 alt and stock 1986 bracket. Well, the plugs are different on the two alternators. The new one requires a new plug, which I found at Pep Boys, but it has three wires instead of two like my stock 1986 alternator. Now, can I wire up the new plug to my existing harness and cap off the third brown wire or do I need to use it in order for the alternator to function properly? Thanks for any help. Here is a thread with my setup(different person) to give you an idea of what I am talking about: https://www.thirdgen.org/techbb2/sho...hreadid=293794

 

Connect the red wire from the original alt plug to the S terminal on the new alternator (should also be a red wire). Connect the other wire from the original alt plug to the I terminal.

The connectors should be labeled on the new plug, and also on the regulator (where the plug goes in the alt)