The voltage regulator is contained within the alternator. On the Tacoma, it is usually combined with the brush holder, meaning you must replace both if you need to replace one. Fortunately, the Tacoma is one truck in which you can work on the alternator.
Disconnect the negative cable on the Tacoma's battery before working on any electrical components. Disconnect the wiring connected to the back of the alternator. Lift the rubber boot and remove the nut on the external terminal and wire.
Loosen the alternator's locknut and pivot bolt, then the nut and adjusting bolt. Push the alternator towards the engine and remove the drive belt. Disconnect the wiring harness, remove all the nuts and bolts you loosened, then remove the alternator.
Remove the rear cover on the alternator and the screws holding the voltage regulator and brush holder.
Install the replacement voltage regulator/brush holder into the alternator. Connect the rear cover back onto the alternator.
Place the alternator back into position on the engine and loosely install the pivot and adjusting bolts. Install the drive belt to its proper tension, and then tighten the locknut and the pivot bolt.
Connect the wire to the alternator terminal and tighten the nut over it. Fit the rubber boot back over the terminal and attach the wire harness connector. Reconnect the negative battery cable.
