Jeep 1997 Grand Cherokee Service Manual page 326

NUMBER
8B - 8 STARTING SYSTEMS
DIAGNOSIS AND TESTING (Continued)
RELAY TEST
The starter relay is located in the Power Distribu-
tion Center (PDC) in the engine compartment. Refer
to the PDC label for starter relay identification and
location.
Remove the starter relay from the PDC as
described in this group to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test procedure
in this group. If not OK, replace the faulty relay.
Starter Relay
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the starter solenoid field coils. There should be
continuity between the cavity for relay terminal 87
and the starter solenoid terminal at all times. If OK,
go to Step 4. If not OK, repair the open circuit to the
starter solenoid as required.
(4) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is energized when
the ignition switch is held in the Start position. On
vehicles with a manual transmission, the clutch
TERMINAL LEGEND COMMON FEED IDENTIFICATION
COIL GROUND
COIL BATTERY
NORMALLY OPEN
NORMALLY CLOSED
5 ohms. If OK, go to Step
pedal must be fully depressed for this test. Check for
battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position, and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK with an
automatic transmission, check for an open or short
circuit to the ignition switch and repair, if required.
If the circuit to the ignition switch is OK, see the
Ignition Switch Test procedure in this group. If not
OK with a manual transmission, check the circuit
between the relay and the clutch pedal position
switch for an open or a short. If the circuit is OK, see
the Clutch Pedal Position Switch Test procedure in
this group.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. On vehicles with an
automatic transmission, it is grounded through the
park/neutral position switch only when the gearshift
selector lever is in the Park or Neutral positions. On
vehicles with a manual transmission, it is grounded
at all times. Check for continuity to ground at the
cavity for relay terminal 85. If not OK with an auto-
matic transmission, check for an open or short circuit
to the park/neutral position switch and repair, if
required. If the circuit is OK, see the Park/Neutral
Position Switch Test procedure in this group. If not
OK with a manual transmission, repair the circuit to
ground as required.
PARK/NEUTRAL POSITION SWITCH TEST
(1) Place the transmission gear selector lever in
the Park position.
(2) Disconnect and isolate the battery negative
cable.
(3) Raise and support the vehicle.
(4) Unplug the park/neutral position switch wire
harness connector.
(5) Check for continuity between the center switch
terminal and a good chassis ground. There should be
continuity. If OK, go to Step 6. If not OK, replace the
faulty switch.
(6) Move the transmission gear selector lever to
the Reverse position and check for continuity
between the center switch terminal and a good chas-
sis ground. There should be no continuity. If not OK,
replace the faulty switch.
CLUTCH PEDAL POSITION SWITCH TEST
The clutch pedal position switch is integral to the
clutch pedal pushrod. It is located near the dash
panel under the instrument panel. The wire harness
connector for the switch is wrapped with foam tape.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the clutch pedal position switch wire
harness connector.
ZG