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How to Wire a Tractor Voltage Regulator

by Ryan Hotchkiss

A voltage regulator takes current from a battery with oscillating voltage and puts out constant voltage. Six-volt generators and 12-volt alternators require current at voltages. Fluctuation in voltage can harm these electrical mechanisms. A tractor's regulator takes the voltage provided by the battery, manages it by reducing it, and sends it on to the alternator or generator at a constant volume that the alternator sends on to the coil. There are three wires that must be connected to the correct regulator terminal.


Weld the regulator mount to the tractor frame. Weld the mount between the alternator or generator mount and the coil housing. Follow the regulator manual's mounting instructions for the proper positioning of the mount. Some recommend a vertical mount while others require horizontal positioning.


Attach the regulator to the mount. Screw or bolt the four corners of the regulator to the mount. Typically, this requires four screws or bolts and four washers and nuts. Do not over tighten the bolts or you will damage the regulator housing, particularly if the housing is plastic.


Connect the positive battery cable wire -- usually red -- to the regulator. Connect the wire to the terminal marked "B" (sometimes this terminal is marked "BATT"). Connect the generator or alternator wire to the regulator. The corresponding terminal for the generator/alternator wire is marked an "A" or "G" (sometimes "ARM" or "GEN"). Connect the field wire -- field coil wire -- to the field terminal on the regulator. An "F" or "FIE" indicates the field terminal.


Polarize the generator or alternator through the regulator. Touch one end of the jumper wire to the battery terminal on the regulator. Touch the other end of the wire to the field terminal. Hold it on the terminal for one second, then remove it. You will damage the regulator if you hold the jumper wire to the battery and field terminals for more than a second.

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