Alternator wiring problem

I can't figure out how the 3 wires on the connector go because there's only 2 wires there for me to use. One is red and the other is a greenish color. The connector has 3 a blue a black and a red wire which is thicker the other 2. Tried a few ways and still can't get the car to even start for more then 2 seconds. Tried to read a few of the diagrams I can't tell what was where or what on them at all. Was wondering if there was anything that could show me in steps how to connect the wires to the right spot. I'm sure the colors are different. I tried the thick red wire to the back of the positive terminal and the back of the alternator and both wires to the other 2 that are there tried them both ways on. And neither way worked. I didn't take the wires off so I didn't get to see what was what before hand. Changed probably a 100 alternators in my life and never had a problem like this. Thank you for anything thing that can help me out.