Dodge ram truck 3500 1996 Service Manual page 391

BR
IGNITION SYSTEM 8D - 9
DIAGNOSIS AND TESTING (Continued)
To test the secondary resistance of each individual
paired coil, attach an ohmmeter across the coil tow­
ers (Fig. 15) or (Fig. 16). This must be done between
corresponding cylinders number 3/2, 7/4, 1/6, 9/8 or
5/10 (Fig. 14). Refer to (Fig. 19) for resistance speci­
fications.
To test the primary resistance of the front coil
pack, attach an ohmmeter between the B+ coil termi­
nal and either the right (cylinders 3/2), center (cylin­
ders 7/4) or left coil (cylinders 1/6) terminals (Fig.
17). Refer to (Fig. 19) for resistance specifications.
To test the primary resistance of the rear coil pack,
attach an ohmmeter between the B+ coii terminal
and either the right (cylinders 9/8) or left (cylinders
5/10) coil terminals (Fig. 18). Refer to (Fig. 19) for
resistance specifications.
OHMMETER
MAKE OHMMETER
C O N N E C T I O N S AT
C O R R E S P O N D I N G CYLINDERS
(1/6, 7/4 O R 3/2).
FRONT
OF
E N G I N E
J948D-14
Fig. 15 Checking Coil Secondary Resistance—Front
Coils—8.0L V-10 Engine
FAILURE TO START TEST—3.9L/5.2L/5.9L
ENGINES
To prevent unnecessary diagnostic time and wrong
test results, the Testing For Spark At Coil test
should be performed prior to this test.
WARNING: SET PARKING BRAKE OR BLOCK THE
DRIVE WHEELS BEFORE PROCEEDING WITH THIS
TEST.
(1) Unplug the ignition coil harness connector at
the coil (Fig. 13).
OHMMETER
MAKE OHMMETER
C O N N E C T I O N S AT
C O R R E S P O N D I N G CYLINDERS
(5/10 OR 9/8).
FRONT
O F
E N G I N E
J948D-15
Fig. 16 Checking Coil Secondary Resistance—Rear
Coils—8.0L V-10 Engine
B+ TERMINAL
TO
CENTER
COIL
J948D-16
Fig. 17 Checking Coil Primary Resistance—Front
Coils—8.0L V-10 Engine
(2) Connect a set of small jumper wires (18 gauge
or smaller) between the disconnected harness termi­
nals and the ignition coil terminals. To determine
polarity at connector and coil, refer to the Wiring
Diagrams section.
(3) Attach one lead of a voltmeter to the positive
(12 volt) jumper wire. Attach the negative side of
voltmeter to a good ground. Determine that sufficient
battery voltage (12.4 volts) is present for the starting
and ignition systems.