Actron Sunpro CP7673 - Ignition Coil Primary Resistance Test

D. Connect the test clips from ( GM - disconnected green “Q” wire and white “W”
wire at distributor), (CHRYSLER - across pins 4 and 5 of harness to distribu-
tor), (FORD and 1978 and up AMC - across pins 2 and 3 of harness to
distributor), (AMC through 1977 - across terminals of harness to distributor.)
E. Observe the appropriate OHMS scale for your vehicle.
RESULTS: OHMS NOT WITHIN SPECIFICATIONS — Defective pickup coil. REPLACE.
OHMS WITHIN SPECIFICATIONS — Pickup coil is OK.
SPECIFICATIONS: GM - 500 to 1,500 OHMS; CHRYSLER - 150 to 900 OHMS; FORD and
1978 and up AMC - 400 to 800 OHMS; AMC through 1977 - 1.6 to 2.4 OHMS.
NOTE: For any vehicle not mentioned here, refer to the vehicle’s service manual for
pickup coil test procedure and specifications.
3. IGNITION COIL PRIMARY RESISTANCE TEST
OHM o
T â HIGH | AMP È
di VOLTS £
E> LOW | DWELL S
RPM
NO CONNECTION NECESSARY
auzenns?
A. Turn the test selector to the OHMS position and put the range switch in the
LOW position. Refer to the OHMS CALIBRATION page at the beginning of
this manual and calibrate the LOW OHMS scale.
NOTE: Make sure the ignition switch is in the OFF position before proceeding.
B. On GM HEI (8 cyl. only) remove the distributor cap from the distributor and
disconnect the harness connector plug at the distributor cap. No disconnect is
necessary for any other vehicle.
C. Connect the test clips to the ignition coil primary terminals (on GM 8-cylinder
vehicles, connect across distributor cap “BAT” and “TACH” terminals).
D. Observe the LOW OHMS scale.
RESULTS: READING IS MORE THAN 2.0 OHMS — Open primary windings of coil.
REPLACE.
READING IS LESS THAN 2.0 OHMS — Primary windings of ignition
coil are OK.
21