Dodge ram truck 3500 1996 Service Manual page 631

8W - 21 STARTING SYSTEM 8W - 21 -1
8W-21 STARTING SYSTEM
D E S C R I P T I O N A N D O P E R A T I O N
AUTOMATIC TRANSMISSION
- The Power Distribution Center (PDC) supplies bat­
tery voltage to the engine starter motor solenoid on
circuit T40 when the coil side of the engine starter
motor relay energizes.
Circuit AO from the battery is triple crimped at the
positive battery post. One branch of circuit AO (bat­
tery positive cable) connects to the starter motor. The
other AO branch supplies voltage to a bus bar in the
PDC. Fuse 2 (40 amp) connects to the bus bar and
protects circuit A2. Circuit A2 connects to the contact
side of the engine starter motor relay.
When the ignition switch is in the START position
it connects circuit A l from fuse 3 in the PDC to cir­
cuit A41. Circuit A41 connects to circuit T141 at the
bypass jumper. Circuit T141 supplies battery voltage
to the coil side of the engine starter motor relay.
Ground for the coil side of the starter motor relay is
supplied by the case grounded PARK/NEUTRAL
position switch. Circuit T41 connects the coil side of
the relay to the PARK/NEUTRAL position switch.
When the starter motor relay energizes and the
contacts CLOSE, circuit T40 supplies battery voltage
to the starter motor solenoid. Circuit AO from the
battery supplies voltage to the starter motor when
the solenoid energizes.
HELPFUL INFORMATION
• Check the fuse located in cavity 2 of the PDC
• The PARK/NEUTRAL position switch CLOSES
when the transmission is in either the PARK or
NEUTRAL positions.
• On diesel engines the T40 circuit is spliced and
supplies power for the fuel shut down relay.
MANUAL TRANSMISSION
The Power Distribution Center (PDC) supplies bat­
tery voltage to the engine starter motor solenoid on
circuit T40 when the coil side of the engine starter
motor relay energizes.
Circuit AO from the battery is triple crimped at the
positive battery post. One branch of circuit AO (bat­
tery positive cable) connects to the engine starter
motor. Another branch of circuit AO supplies voltage
to a bus bar in the PDC. Fuse 2 in the PDC connects
to the bus bar and protects circuit A2. Circuit A2
splices and connects to the contact side of the engine
starter motor relay.
When the ignition switch is in the START position,
it connects circuit A l from fuse 3 in the PDC to cir­
cuit A41. Circuit A41 connects to circuit T141
through the clutch pedal position switch. Circuit
T141 supplies battery voltage to the coil side of the
engine starter motor relay when the operator presses
the clutch pedal and the clutch pedal position switch
CLOSES. Ground for the coil side of the engine
starter motor relay is supplied on circuit T41. This
circuit is connected with circuit Z12. Circuit Z12 con­
nects to ground.
When the starter motor relay energizes and the
contacts CLOSE, circuit T40 supplies battery voltage
to the starter motor solenoid. Circuit AO from the
battery supplies voltage to the starter motor when
the solenoid energizes.
HELPFUL INFORMATION
• Check the fuse located in cavity 2 of the PDC.
• On diesel engines the T40 circuit is spliced and
supplies power to the coil side of the fuel shut down
relay.
S C H E M A T I C S A N D D I A G R A M S
WIRING DIAGRAM INDEX
The following index covers all components found i n
this section of the wiring diagrams. I f the component
you are looking for is not found here, refer to section
8W-02 for a complete list of all components shown i n
the wiring diagrams.