Jeep 1997 Grand Cherokee Service Manual page 443

ZG
DIAGNOSIS AND TESTING (Continued)
OK, go to Step 7. If not OK, repair the short circuit
as required.
(7) Check for continuity between the radio control
mux circuit cavities of the remote radio switch wire
harness connector and the BCM wire harness connec-
tor. There should be continuity. If OK, refer to the
proper Body Diagnostic Procedures manual to test
the BCM and the CCD data bus. If not OK, repair
the open circuit as required.
SPEAKER
For circuit descriptions and diagrams, refer to
8W-47 - Audio System 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.
CAUTION: The speaker output of the radio is a
"floating ground" system. Do not allow any speaker
lead to short to ground, as damage to the radio
may result.
(1) Turn the ignition switch to the On position.
Turn the radio on. Adjust the balance and fader con-
trols to check the performance of each individual
speaker. Note the speaker locations that are not per-
forming correctly. Go to Step 2.
(2) Turn the radio off. Turn the ignition switch to
the Off position. Disconnect and isolate the battery
negative cable. Remove the instrument cluster bezel
and remove the radio as described in this group. If
the vehicle is equipped with the Infinity Gold
speaker package, also unplug the wire harness con-
nectors at the amplifier. Check both the speaker feed
(+) circuit and return (-) circuit cavities for the inop-
erative speaker location(s) at the radio wire harness
connectors for continuity to ground. In each case,
there should be no continuity. If OK, go to Step 3. If
not OK, repair the shorted speaker circuit(s) as
required.
(3) If the vehicle is equipped with the Infinity Gold
speaker package, go to Step 6. If the vehicle is
equipped with the standard speaker system, check
the resistance between the speaker feed (+) circuit
and return (-) circuit cavities of the radio wire har-
ness connectors for the inoperative speaker loca-
tion(s). The meter should read between 3 and 8 ohms
GROUP 8M - PASSIVE
STEERING COLUMN,
(speaker resistance). If OK, go to Step 4. If not OK,
go to Step 5.
(4) Install a known good radio. Connect the bat-
tery negative cable. Turn the ignition switch to the
On position. Turn on the radio and test the speaker
operation. If OK, replace the faulty radio. If not OK,
turn the radio off, turn the ignition switch to the Off
position, disconnect and isolate the battery negative
cable, remove the test radio, and go to Step 5.
(5) Unplug the speaker wire harness connector at
the inoperative
between the speaker feed (+) circuit cavities of the
radio wire harness connector and the speaker wire
harness connector. Repeat the check between the
speaker return (-) circuit cavities of the radio wire
harness connector and the speaker wire harness con-
nector. In each case, there should be continuity. If
OK, replace the faulty speaker. If not OK, repair the
OR
open circuit(s) as required.
(6) For each inoperative speaker location, check for
continuity between the speaker feed (+) circuit cavi-
ties of the radio wire harness connectors and the
amplifier wire harness connectors. Repeat the check
for each inoperative speaker location between the
speaker return (-) circuit cavities of the radio wire
harness connectors and the amplifier wire harness
connectors. In each case, there should be continuity.
If OK, go to Step 7. If not OK, repair the open circuit
as required.
(7) Check for continuity between the two ground
circuit cavities of the amplifier wire harness connec-
tor and a good ground. There should be continuity. If
OK, go to Step 8. If not OK, repair the open circuit(s)
as required.
(8) Check the amplifier fuse in the junction block.
If OK, go to Step 9. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(9) Check for battery voltage at the amplifier fuse
in the junction block. If OK, go to Step 10. If not OK,
repair the open circuit to the PDC as required.
(10) Install the radio. Connect the battery negative
cable. Check for battery voltage at the two fused B(+)
circuit cavities of the amplifier wire harness connec-
tor. If OK, go to Step 11. If not OK, repair the open
circuit to the fuse in the junction block as required.
(11) Turn the ignition switch to the On position.
Turn the radio on. Check for battery voltage at the
radio 12 volt output circuit cavity of the amplifier
wire harness connector. If OK, go to Step 12. If not
OK, repair the open circuit to the radio as required.
(12) Turn the radio off. Turn the ignition switch to
the Off position. Disconnect and isolate the battery
negative cable. For each inoperative speaker location,
check both the amplified feed (+) circuit and the
amplified return (-) circuit cavities of the amplifier
AUDIO SYSTEMS
speaker. Check for
8F - 7
continuity