How to Wire an External Alternator Regulator

alternator inside an engine
  • 2-4 hours
  • Intermediate
  • 50-100
What You'll Need
A drill & 1/8 bit
A screwdriver
A soldering iron
A volt meter
A wire stripper/knife
A crimping tool
Wire cutters
Pin-out diagram from the Service Manual
Voltage regulator - AC
Plug with pigtails for regulator
3 x 18 16awg wires (preferably green, blue and black)
1 x crimp loop connector
Electrical tape or shrink tube
Zip ties
Wire loom
2 self-tapping sheet metal screws

If your alternator does not charge, or your alternator was overcharging, it will most likely fail. To resolve this problem you can actually wire in a external alternator regulator, which allows convenient switching to your internal regulator once your power module works.

Step 1 - Install the Wires to the Alternate Regulator

Position the alternate regulator on the side of the driver shock tower, which is next to the relays. Mark the area and drill holes for mounting of bolts. Connect the blue and green wirings to the blue and green leads found on the regulator. Don’t worry if the colors don’t match because these are interchangeable. The colored green wire goes to the center pin of the regulator while the blue wire goes to the side pin. Secure the wires by taping or shrinking the joints using an electrical tape or shrink tube. Tuck the wire loop under the black wire using the crimping tool.

Step 2 - Install the Regulator to the Shock Tower

voltage regulator

Attach the regulator to the shock tower by connecting the black wiring without the loop to a mounting screw and then install the plug with pigtails for the regulator, and make sure that there is good grounding. Check the upper plug located on your power module or simply plug in cars that are new. You can refer to your pin out diagram from the service manual to guide you in finding the two field wires from your regulator. Make sure there is continuity on the wirings from its field terminal down to the alternator. Then find the J2 or key on hot circuit on the same connector and confirm it with the 12v key on.

Step 3 - Secure the Newly Connected Wirings

Make sure to unplug the upper plug of the power module and disconnect its battery even though it’s not working. Then strip 1/2”-3/4” of insulation off the identified three wirings, simply strip and do not cut these insulators. Now connect the green wiring starting from the regulator down to the identified green field wire, the regulator blue wiring towards the blue (“J2” switched 12v) and lastly the black ground wire towards the alternator field wire. Secure the joints with an electrical tape; do this thoroughly.

Use the wire looms and zip ties to guide and direct the wirings and also to keep it protected. Afterwards, you may check the car with a voltage test by reconnecting the battery and turning on the automobile.