Jeep 1996 Grand Cherokee Service Manual - page 335
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 radio on. Adjust the balance and fader
controls 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. Disconnect and isolate the
battery negative cable. Remove the instrument clus-
ter bezel and remove the radio. If equipped with the
Infinity Gold speaker package, also unplug the con-
nectors at the amplifier. Check both the speaker feed
(+) circuit and return (-) circuit cavities at the radio
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 equipped with the Infinity Gold speaker
package, go to Step 6. If equipped with the standard
speaker system, check the resistance between the
speaker feed (+) circuit and return (-) circuit cavities,
for each speaker location. The meter should read
between 3 and 8 ohms (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 on the radio and test the
speaker operation. If OK, replace the faulty radio. If
not OK, disconnect and isolate the battery negative
cable, remove the test radio, and go to Step 5.
(5) Unplug the speaker wiring connector at the
speaker. Check for continuity between the speaker
feed (+) circuit cavities of the radio connector and the
speaker connector. Repeat the check between the
speaker return (-) circuit cavities of the radio connec-
tor and the speaker connector. In each case, there
should be continuity. If OK, replace the faulty
speaker. If not OK, repair the open circuit(s) as
required.
(6) Check for continuity between the speaker feed
(+) circuit cavities of the radio connector and the
amplifier connector. Repeat the check between the
speaker return (-) circuit cavities of the radio connec-
tor and the amplifier connector. 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 connector 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, replace the faulty
fuse.
(9) Install the radio. Connect the battery negative
cable. Check for battery voltage at the two fused B(+)
circuit cavities of the amplifier connector. If OK, go to
Step 10. If not OK, repair the open circuit as
required.
(10) Turn the ignition switch and radio switch to
the On position. Check for battery voltage at the
radio 12 volt output circuit cavity of the amplifier
connector. If OK, go to Step 11. If not OK, repair the
open circuit as required.
(11) Turn the radio switch and the ignition switch
to the Off position. Check both the amplified feed (+)
circuit and the amplified return (-) circuit cavities of
the amplifier connectors for continuity to ground. In
each case there should be no continuity. If OK, go to
Step 12. If not OK, repair the short circuit as
required.
(12) Check the resistance between the amplified
feed (+) circuit and the amplified return (-) circuit
cavities of the amplifier connectors, for each speaker
position. The meter should read between 3 and 8
ohms (speaker resistance). If OK, replace the faulty
amplifier. If not OK, go to Step 13.
(13) Unplug the speaker wiring connector at the
speaker. Check for continuity between the speaker
feed (+) circuit cavity of the speaker connector and
the amplified feed (+) circuit cavity of the amplifier
connector. Repeat the check for the return (-) circuit.
In each case there should be continuity. If OK,
replace the faulty speaker. If not OK, repair the open
circuit as required.
ANTENNA
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS,
REFER
TO
GROUP
8M
-
PASSIVE
RESTRAINT
SYSTEMS
BEFORE
ATTEMPTING
STEERING
WHEEL,
STEERING
COLUMN,
OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The following four tests are used to diagnose the
antenna with an ohmmeter:
• Test 1 - Mast to ground test
• Test 2 - Tip-of-mast to tip-of-conductor test
• Test 3 - Body ground to battery ground test
• Test 4 - Body ground to coaxial shield test.
The ohmmeter test lead connections for each test
are shown in Antenna Tests (Fig. 1).
NOTE: This model has a two-piece antenna cable.
Tests 2 and 4 must be conducted in two steps to
isolate a coaxial cable problem; from the coaxial
cable connection under the right end of the instru-
ment panel near the right cowl side panel to the
antenna base, and then from the coaxial cable con-
nection to the radio chassis connection.
8F - 6
AUDIO SYSTEMS
ZJ
DIAGNOSIS AND TESTING (Continued)