alt wires

[chpr1972]

I need clarification.
On a Si alternator I have 4 terminals. The red S wire I should run to the battery because it senses voltage in the system. I could splice it in near the starter somewhere but directly to the battery will be easier.

the brown F wire goes to the ignition switch.

The other brown wire goes to the idiot lite which I do not have as I have a Dakota Digital Dash. Do I need to wire this some where or can I not use it.

Also which wire for sure do I put a resistor in and how big of a resistor. The gray P wire I do not use.

[TheJDMan]

That is incorrect. Both the 10SI and 12SI are three wire internally regulated alternators as delivered by GM. The sensing wire needs to be routed to the cars main power bus in order to detect the total electrical load. The field wire is connected to a switched 12v source and may need an inline diode to eliminate backfeed. The output/charge wire is connected to the battery. Read the tech articles from Mad Electrial, there are several articles at the link below relating to SI alternator wiring that will answer your questions and also explain what you are trying to achieve in wiring an SI style alt.

http://madelectrical.com/electrical-tech.shtml