Ford Ranger/Bronco II 1983-1990 Repair Guide



The alternator regulator has been designed to control the charging system's rate of charge and to compensate for seasonal temperature changes. This regulator is 100 percent solid state, consisting of transistors, diodes, and resistors. The operating functions are achieved in basically four circuits: The output stage, the voltage control stage, the solid state relay, and the field circuit overload protection stage. There are two different regulators used on your Ford vehicle. The units both look alike, but are not interchangeable due to the different wiring connector plugs. One unit is used on trucks equipped with an ammeter and the other is used on alternator warning light equipped trucks. The regulators are calibrated by the manufacturer and no adjustment is required or possible on these units.


See Figure 1

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Fig. Fig. 1: Exploded view of the regulator assembly mounting

  1. Disconnect the positive terminal of the battery.
  3. Disconnect all of the electrical leads at the regulator. Label them as removed, so you can replace them in the correct order on the replacement unit.
  5. Remove all of the hold-down screws, then remove the unit from the vehicle.
  7. Install the new voltage regulator using the hold-down screws from the old one, or new ones if they are provided with the replacement regulator. Tighten the hold-down screws.
  9. Connect all the leads to the new regulator.