Mustang Powermaster 100 Amp Alternator (1965-1993) Installation Instructions
1. To start installing your new Mustang Powermaster 8-57100 100 Amp Single Wire Alternator
, you want to disconnect the battery, then disconnect the two connectors on the back of the old alternator. Use a breaker bar to loosen the tensioner and remove the belt, then remove the two bolts holding the alternator in place. This will allow you to completely remove the old alternator. Install the new alternator and secure it with the two bolts.
2. Remove the battery and the Mustang battery tray
. There are two bolts on the battery tray that go through the fender, and you will need to hold the nuts to loosen them. The back one is hard to get to because you have to work around the washer fluid tank, but the tank does not need to be removed. I found vise grips helpful for removing these bolts.
4. Remove all of the lights in the front and the wires to the Mustang horn
5. The harness has two connectors up by the Mustang starter solenoid
. Disconnect them, along with the single wire going to the starter solenoid. I recommend putting the nut immediately back on the solenoid to prevent the other wires from coming off.
6. Remove the entire harness from the car, lay it out flat and remove the plastic tubing and the tape from it.
7. Find the wires that are from the Mustang alternator
. There should be black with yellow, green/orange, and yellow. Remove them from the harness. You will have to cut the green wire, which goes to the smaller connecter. I left some slack on mine in case I needed it, but ended up not needing it, so leave just enough to blend in to the wiring harness.
8. The 4 gauge wire will not fit in the plastic tubing, so just tape up the wiring harness for the Mustang headlights
and turn signals, and put the plastic tubing back on.
9. Now you're going to have to cut the wire to the right length. Before cutting, strip off one end of the wire and put on 1 or 2 pieces of shrink tube. Put a small amount of dielectric grease in the connector and crimp the wire in. If there’s any excess grease remove it, then bring the shrink tube up the connector and use a lighter to reduce it. I used two pieces to be sure.
10. Put the connector on the Mustang alternator
and bring the wire around, either like the alternator wires were ran in stock form, or any way you want to run it. Run it to the starter solenoid, then mark where the cut should be. Cut the wire, then install the connector, just like you did for the other end.
11. Then, reinstall the wiring harness for the lights, along with the 4 gauge wire for the Powermaster
alternator. Zip tie it to the lighting harness. Cut off the excess from the zip ties.
12. Hook the lighting harness back up. Then, put the radiator brackets back on.
13. Put the battery tray back, then put the Mustang battery
back in and hook it up.