Jeep 1997 Grand Cherokee Service Manual page 473

ZG
DIAGNOSIS AND TESTING (Continued)
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL,
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
TURN SIGNAL AND HAZARD WARNING SYSTEMS
For circuit descriptions and diagrams, refer to
8W-52 - Turn Signals in Group 8W - Wiring Dia-
grams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL,
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Turn the ignition switch to the On position.
Actuate the turn signal lever or the hazard warning
button. Observe the turn signal indicator lamp(s) in
the instrument cluster. If the flash rate is very high,
check for a turn signal bulb that is not lit or is very
dimly lit. Repair the circuits to that lamp or replace
the faulty bulb, as required. Test the operation of the
turn signal and hazard warning systems again. If the
turn signal indicator(s) fail to light, go to Step 2.
(2) Turn the ignition switch to the Off position.
Check the turn signal fuse in the junction block
and/or the hazard warning fuse in the Power Distri-
bution Center (PDC). If OK, go to Step 3. If not OK,
repair the shorted circuit or component as required
and replace the faulty fuse(s).
(3) Turn the ignition switch to the On position to
check for battery voltage at the turn signal fuse in
the junction block; or, leave the ignition switch in the
Off position to check for battery voltage at the haz-
ard warning fuse in the PDC. If OK, go to Step 4. If
not OK, repair the open circuit as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Unplug the combination flasher from the junction
block and replace it with a known good unit. Connect
the battery negative cable. Test the operation of the
turn signal and hazard warning systems. If OK, dis-
card the faulty combination flasher. If not OK,
remove the test flasher and go to Step 5.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
GROUP 8M - PASSIVE
STEERING COLUMN,
GROUP 8M - PASSIVE
STEERING COLUMN,
TURN SIGNAL AND HAZARD WARNING SYSTEMS
output circuit cavity for the combination flasher in
the junction block. If OK, go to Step 6. If not OK,
repair the open circuit to the turn signal fuse as
OR required.
(6) Turn the ignition switch to the Off position.
Check for battery voltage at the fused B(+) circuit
cavity for the combination flasher in the junction
block. If OK, go to Step 7. If not OK, repair the open
circuit to the hazard warning fuse as required.
(7) Disconnect and isolate the battery negative
cable. Check for continuity between the ground cir-
cuit cavity for the combination flasher in the junction
block and a good ground. There should be continuity.
If OK, go to Step 8. If not OK, repair the circuit to
ground as required.
(8) Unplug the multi-function switch wire harness
connector as described in this group. Check for con-
tinuity between the combination flasher hazard sig-
nal circuit cavities in the junction block and in the
OR
multi-function switch wire harness connector. There
should be continuity. If OK, go to Step 9. If not OK,
repair the open circuit as required.
(9) Check for continuity between the combination
flasher turn signal circuit cavities in the junction
block and in the multi-function switch wire harness
connector. There should be continuity. If OK, test the
multi-function switch as described in this group. If
not OK, repair the open circuit as required.
MULTI-FUNCTION SWITCH
Perform the diagnosis of the hazard warning
and/or turn signal systems as described in this group
before testing the multi-function switch. For circuit
descriptions and diagrams, refer to 8W-52 - Turn Sig-
nals in Group 8W - Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL,
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Unplug the multi-function switch wire harness
connector as described in this group.
(2) Using an ohmmeter, perform the switch conti-
nuity checks at the switch terminals as shown in the
Multi-Function Switch Continuity chart (Fig. 2).
(3) If the switch fails any of the continuity checks,
replace the faulty switch. If the switch is OK, repair
the lighting circuits as required.
TO GROUP 8M -
STEERING COLUMN,
8J - 3
PASSIVE
OR