Diagnosis And Testing - Antenna Body And Cable

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 antenna coaxial cable shield test.

The ohmmeter test lead connections for each test are shown in the illustration.

Courtesy of CHRYSLER GROUP, LLC

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 body. Check the ohmmeter reading for continuity.
3. There should be no continuity. If OK, go to Test 2  . If not OK, replace the shorted 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.
2. Touch one ohmmeter test lead to the tip of the antenna mast. Touch the other test lead to the center conductor pin of the instrument panel antenna cable coaxial connector for the radio. Check the ohmmeter reading for continuity.
3. There should be continuity. The ohmmeter should register only a fraction of an ohm resistance. High or infinite resistance indicates a damaged or open antenna conductor. If OK, go to Test 3  . If not OK, isolate and test each of the individual antenna conductor components. Replace only the ineffective antenna conductor component.

TEST 3 

- Test 3 checks the condition of the vehicle body ground connection. To begin this test, proceed as follows:

1. This test must be performed with the battery positive cable disconnected from the battery. Disconnect and isolate both battery cables, negative cable first.
2. Reconnect the battery negative cable.
3. Touch one ohmmeter test lead to a good clean ground point on the vehicle right fender panel. Touch the other test lead to the battery negative terminal post. Check the ohmmeter reading for continuity.
4. There should be continuity. The ohmmeter should register less than one ohm resistance. High or infinite resistance indicates a loose, corroded or damaged connection between the battery negative terminal and the vehicle body. If OK, go to Test 4  . If not OK, check the battery negative cable connection to the vehicle body and the radio noise suppression ground strap connections to the engine and the vehicle body for being loose or corroded. Clean or tighten these connections as required.

TEST 4 

- Test 4 checks the condition of the connection between the antenna coaxial cable shield and the vehicle body ground 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 a good clean ground point on the vehicle right fender panel. Touch the other test lead to the outer crimp on the antenna coaxial cable connector under the right end of the instrument panel near the right cowl side inner panel. Check the ohmmeter reading for continuity.
3. There should be continuity. The ohmmeter should register less than one ohm resistance. High or infinite resistance indicates a loose, corroded or damaged connection between the antenna body and the vehicle body or between the antenna body and the antenna coaxial cable shield. If not OK, clean the antenna body to right fender panel mating surfaces and tighten the antenna mounting nut to specifications.
4. Check the resistance again with an ohmmeter. If the resistance is still more then one ohm, replace the ineffective antenna body and cable.

For additional diagnosis of an AM/FM reception issue, perform the POOR OR NO AM/FM AUDIO RECEPTION  test. Refer to: POOR OR NO AM/FM AUDIO RECEPTION .