Motorcraft External Voltage Regulator (EVR) System

Fig. 7 Regulator Plug Jumper Wire Connection:

Fig. 8 Rear Terminal Alternator. Jumper Wire Connection:

Fig. 9 Side Terminal Alternator. Jumper Wire Connection:

1. If voltmeter reading indicates 2 volts over battery voltage (over voltage), proceed as follows:
a. Stop the engine and check the ground connections between the regulator and alternator and/or regulator to engine. Clean and tighten connections securely and repeat the Charging System Test Procedures.
b. If over voltage condition still exists, disconnect regulator wiring plug from regulator and repeat the Charging System Test Procedures.
c. If over voltage still exists with the regulator wiring plug disconnected, repair the short in the wiring harness between the alternator and regulator. Then, replace the regulator and connect the regulator wiring plug to the regulator and repeat the Charging System Test Procedures.
2. If voltmeter does not indicate more than 1/2 volt above battery voltage, proceed as follows:
a. Disconnect voltage regulator wire connector and connect an ohmmeter between wire connector ``F'' terminal and ground. If reading is less or 2.4 ohms, repair grounded field circuit and repeat Charging System Test procedure.
b. If ohmmeter reading is more than 2.4 ohms, connect a jumper wire between voltage regulator wire connector terminals A and F, Fig. 7, then repeat Charging System Test procedure. If voltmeter reading is now more than 1/2 volt above battery voltage, the voltage regulator or wiring is defective, refer to Regulator Test.
c. If voltmeter still indicates less than 1/2 volt, disconnect jumper wire from voltage regulator wire connector and leave connector disconnected from regulator. Connect a jumper wire between alternator FLD and BAT terminals, Figs. 8 and 9, then repeat Charging System Test procedures.
d. If voltmeter reading now indicates 1/2 volt or more above battery voltage, repair alternator to regulator wiring harness.
e. If voltmeter still indicates less than 1/2 volt above battery voltage, stop engine and move voltmeter positive lead to alternator BAT terminal.
f. If voltmeter now indicates battery voltage, the alternator should be removed, inspected and repaired. If zero volts is indicated, repair BAT terminal wiring.