Ford Ranger/Explorer/Mountaineer 1991-1999

Alternator Precautions


To prevent damage to the alternator and regulator, the following precautions should be taken when working with the electrical system.

Never reverse the battery connections.
Booster batteries for starting must be connected properly: positive-to-positive and negative-to-ground.
Disconnect the battery cables before using a fast charger; the charger has a tendency to force current through the diodes in the opposite direction for which they were designed. This burns out the diodes.
Never use a fast charger as a booster for starting the vehicle.
Never disconnect the voltage regulator while the engine is running.
Avoid long soldering times when replacing diodes or transistors. Prolonged heat is damaging to AC generators.
Do not use test lamps of more than 12 volts (V) for checking diode continuity.
Do not short across or ground any of the terminals on the AC generator.
The polarity of the battery, generator, and regulator must be matched and considered before making any electrical connections within the system.
Never operate the alternator on an open circuit. make sure that all connections within the circuit are clean and tight.
Disconnect the battery terminals when performing any service on the electrical system. This will eliminate the possibility of accidental reversal of polarity.
Disconnect the battery ground cable if arc welding is to be done on any part of the vehicle.