Grand Cherokee 2WD V8-4.7L VIN J (2004)
Antenna Cable: Testing and Inspection
Antenna Body & Cable
DIAGNOSIS AND TESTING - ANTENNA BODY AND CABLE
The following four tests are used to diagnose the antenna with an ohmmeter:
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Test 1 - Mast to ground test
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Test 2 - Tip-of-mast to tip-of-conductor test
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Test 3 - Body ground to battery ground test
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Test 4 - Body ground to antenna coaxial cable shield test.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT
AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM
CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO
DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Fig.3 Antenna Tests - Typical
The ohmmeter test lead connections for each test are shown in the illustration.
NOTE:
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This model has a two-piece antenna coaxial cable. Tests 2 and 4 must be conducted in two steps to isolate an antenna cable problem. First, test the
primary antenna cable (integral to the antenna body and cable) from the coaxial cable connector under the right end of the instrument panel near
the right cowl side inner panel to the antenna body. Then, test the secondary antenna cable (instrument panel antenna cable) from the coaxial cable
connector under the right end of the instrument panel near the right cowl side inner panel to the coaxial cable connector at the radio.
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Use extreme caution when checking continuity of center conductor to avoid damage.
TEST 1
Test 1 determines if the antenna mast is insulated from ground. Proceed as follows:
1. Disconnect and isolate the antenna coaxial cable connector under the right end of the instrument panel near the right cowl side inner panel.
2. Touch one ohmmeter test lead to the tip of the antenna mast. Touch the other test lead to the antenna cap nut. Check the ohmmeter reading for
continuity.
3. There should be no continuity. If OK, go to Test 2. If not OK, replace the faulty antenna body and cable.
TEST 2
Test 2 checks the antenna conductor components for an open circuit. This test should be performed first on the entire antenna circuit, from the antenna
mast to the center conductor of the coaxial cable connector at the radio. If an open circuit is detected, each of the three antenna conductor components
(antenna mast, antenna body and primary cable unit, instrument panel antenna secondary cable) should be isolated and tested individually to locate the
exact component that is the source of the open circuit. To begin this test, proceed as follows:
1. Disconnect the instrument panel (secondary) antenna cable coaxial connector from the back of the radio.
