Field Control Relay
- Connect a voltmeter into system at regulator No. 2 terminal to ground. Operate engine at fast idle (1500-2000 RPM) and read voltage. If voltmeter shows zero voltage, check circuit between No. 2 terminal on regulator to "R" terminal on alternator. If voltage at regulator exceeds closing voltage specifications (2.3-3.7 volts), regulator field relay is faulty.
- To adjust, make connections as shown in illustration using a 50 ohm variable resistor. Turn resistor to open position and turn ignition switch "OFF". Slowly decrease resistance and note closing voltage of relay. Adjust by bending heal iron on field relay contacts of regulator.
Courtesy of GENERAL MOTORS COMPANY