alt wiring question ? now with pics

[sweetk30]

i have the old alt style on my 79 truck. i have the full serp setup from a 90-91 and the alt is the newer style. how do i know how to wire it up? any help would be great. thanks.

updated: i am going to this style alt just be clear. thanks.

 

[Russell]

Pretty easily is the answer to that question!

You need one wire to go from the back of the alternator to the distribution block on the firewall (existing) one wire to excite the alternator (12 volts from the back of the Alt is fine) and one wire to go to an idiot light in your dash. Do NOT try and run the alt without that idiot light, or a resistor to replace it, or you'll be getting a new alt.

The excitatory wire is the red wire, and the idiot light wire is the brown wire.

By the way, the other side of the idiot light needs to go to a 12 volt hot source. The Alternator provides ground.