Chevrolet Repair: alternator harness wires, charge amps, size blazer

Question
Hi i have a 94 full size blazer 5.7l on the back of the alternator theres a pulg and a red wire FROM THE PLUG there is 3 wires one is red where does this wire go?

Answer
Hey,

 There are three wires that go to the back of the alternator. The fat red one goes to the battery (thats where the current is returned to a discharged battery and used to supplement the electrical system when load detection creates charge amps).  The two in the plug are for field strength and alternator lamp failure control.

Wayne