I replaced my fire hazard alternator recently with a 3g setup. I got my alternator out of a junked 95 Taurus wagon with the 3.8, and it worked perfectly. I had read that some people here had to swap out the pulleys on the alternators, but I didn't have that issue. The original pulley was about an inch smaller than the 3g one, but it'll still fit on there just fine. There's only one wire you need to change.

On the plug with the two fat black charge wires, there's also a white wire with a black stripe. That's the one wire that needs to be changed. The other plug with the green wire, the white/yellow wire, and the white/black wire plugs directly into the new alternator.

This is what the new alternator looks like. The white/black wire that was cut off of the charge wire plug on the old alternator gets plugged into the single wire connector in the middle of the picture. If you get your alternator from a j/y, like I did, I would recommend grabbing the pigtail for that wire as well, that way you don't have to hack any sort of connector, like I did.

The next step is to run a big fat cable from the stud on the back of the alternator to the + terminal of the battery. I purchased a 4AWG battery cable and cut the ends off. I used some cable lugs that were the appropriate gauge and the right size hole for the stud instead.

You also need to put a fuse or circuit breaker in line with the alternator charge wire. I chose a 175 amp fuse; other people have chosen different ratings.

For now, I hooked the new charge wire to the starter relay, where the old one was hooked up. When I do a wire tuck later, all of this will change, but since I only had the two cable lugs, I wanted to put the fuse at one end of the cable.

The finished connections. The 3-wire plug is hiding underneath the alternator.

The final result: