Hall Control Unit Check

NOTE: For quick check procedures, see HALL GENERATOR CHECK , Quick Check.

Be sure all connectors are securely connected. Connect voltmeter positive lead to ignition coil terminal 15. Attach negative lead to coil terminal 1. Turn ignition "ON." See Fig 1.

Fig 1: Checking Hall Control Unit Check voltage at ignition coil primary terminals.
Reading should be 2 volts, and then fall to 0 (zero) volts after 1-2 seconds. Leave voltmeter connected, but turn ignition "OFF." If voltage reading is correct, replace Hall control unit.
If readings were not to specifications, disconnect 3-wire connector at distributor. Insert a metal pin in center contact of harness connector (Green/White wire). See Fig 2.

Fig 2: Checking Hall Control Unit Momentarily ground pin inserted in center terminal.
Ground metal pin briefly. Turn ignition "ON." Voltage should increase briefly to at least 2 volts. Turn ignition "OFF." Remove pin and reconnect harness connector to distributor.
If test results were satisfactory, proceed to Hall Generator (Sending Unit) Check. If not to specifications, check for open circuit in wiring. If none is found, replace Hall control unit.