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STATES |
DETAILS/RESULTS/ACTIONS |
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H1: CHECKING THE VOLTAGE SUPPLIED TO THE AUDIO UNIT |
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1Disconnect C443 from the audio unit. |
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2Enter the ACCESSORY position. |
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3Measure the voltage between pin 1 of audio unit connector C443, circuit 29-MD15 (OR/BLK), harness side and ground, and between pin 3 of audio unit connector C443, circuit 75-MD15 (GYN/GN), harness side and ground. |
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• Is the voltage greater than 10 V in all cases? |
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→ Yes |
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Go to H2. |
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→ No |
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REPAIR circuit 29-MD15 (orange/black) or circuit 75-MD15 (yellow/green). CHECK for proper system operation. |
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H2: CHECKING THE AUDIO UNIT GROUND CIRCUIT FOR OPENINGS |
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1Enter the OFF position. |
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2Measure the resistance between pin 6 of audio unit connector C443, circuit 91-MD15 (black/green), harness side and ground, and between pin 2 of audio unit connector C443, circuit 91-MD34 (black/yellow), harness side and ground. |
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• Is the resistance less than 5 Ohms in all cases? |
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→ Yes |
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INSTALL the new audio unit. CHECK the system for proper operation. |
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→ No |
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REPAIR electrical circuit 91-MD15 (black/green) or 91-MD34 (black/yellow). CHECK for proper system operation. |
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PINPOINT TEST I: POOR RECEPTION QUALITY
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STATES |
DETAILS/RESULTS/ACTIONS |
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I1: CHECKING THE ANTENNA CABLE SHIELDING |
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1Enter the OFF position. |
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2Enter the OFF position. |
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3Disconnect the Antenna Cable. |
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4Disconnect the antenna cable from the audio unit. |
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5Measure the resistance between the antenna cable ground plug (shield) and ground. |
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• Resistance less than 1 Ohm? |
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→ Yes |
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Go to I2. |
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→ No |
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CLEAN and TIGHTEN the audio unit housing ground and the antenna base to body connection. If the fault is not corrected, INSTALL a new antenna cable. CHECK the system for proper operation. |
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I2: CHECKING THE CENTRAL ANTENNA WIRE FOR AN OPEN CIRCUIT |
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1Remove the antenna mast. |
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2Measure the resistance of the center conductor between the ends of the antenna cable. |
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• Resistance less than 1 Ohm? |
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→ Yes |
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Go to I3. |
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→ No |
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INSTALL a new antenna cable. CHECK that the system is operating correctly. |
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I3: CHECKING THE ANTENNA CABLE FOR A SHORT CIRCUIT |
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1Measure the resistance between the antenna center conductor and the antenna ground (shield). |
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• Resistance greater than 10,000 ohms? |
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→ Yes |
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CLEAN and TIGHTEN the ground connections at the antenna base, on the audio unit housing and the battery ground wire to the body. If the problem persists, INSTALL a new audio unit. CHECK the system for proper operation. |
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→ No |
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INSTALL a new antenna cable. CHECK that the system is operating correctly. |
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PINPOINT TEST J: POOR QUALITY/DISTORTED SOUND IN ONE OR MORE SPEAKERS (NOT ALL SPEAKERS)
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STATES |
DETAILS/RESULTS/ACTIONS |
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J1: CHECK SPEAKER RESISTANCE |
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1Disconnect the non-working speaker. |
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2Measure the resistance between pins 1 and 2 of the non-working speaker, on the element side. |
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• Is the resistance approximately 4.0 ohms? |
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→ Yes |
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Go to J2. |
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→ No |
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INSTALL the new speaker. CHECK the system for proper operation. |
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J2: CHECK SPEAKER INPUT FOR SHORT CIRCUIT "MASS" |
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1Disconnect C443 from the audio unit. |
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2Measure the resistance between pin 1 of the non-working speaker connector, on the wiring side, and ground. |
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• Resistance greater than 10,000 ohms? |
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→ Yes |
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Go to J3. |
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→ No |
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REPAIR the speaker input circuit. CHECK the system for proper operation. |
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J3: CHECK THE SPEAKER RETURN CIRCUIT FOR A SHORT CIRCUIT "MASS" |
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1Measure the resistance between pin 2 of the non-working speaker connector, on the wiring side, and ground. |
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• Resistance greater than 10,000 ohms? |
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→ Yes |
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INSTALL a new speaker. CHECK the system for proper operation. If the problem persists, INSTALL a new audio unit. CHECK the system for proper operation. |
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→ No |
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REPAIR the speaker return circuit. CHECK the system for proper operation. |
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PINPOINT TEST K: NO SOUND FROM ALL SPEAKERS
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STATES |
DETAILS/RESULTS/ACTIONS |
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K1: CHECK THE SPEAKER INPUT CIRCUIT FOR A SHORT CIRCUIT "MASS" |
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1Enter the OFF position. |
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2Disconnect C442 from the audio unit. |
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3Measure the resistance between the following audio unit connector pins and ground: - (Front left speaker) pin 1 of connector C442, electrical circuit 8-MD10 (white-black), on the wiring side, and ground. - (Rear left speaker) pin 3 of connector C442, electrical circuit 8-MD11 (white-green), on the wiring side, and ground. - (Front right speaker) pin 5 of connector C442, electrical circuit 8-MD17 (white-red), on the wiring side, and ground. - (Rear right speaker) pin 7 of connector C442, electrical circuit 8-MD18 (white), on the wiring side, and ground. |
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• Is the resistance greater than 10,000 Ohms in all cases? |
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→ Yes |
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Go to K2. |
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→ No |
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REPAIR the electrical circuit concerned. CHECK the system for proper operation. |
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K2: CHECK THE SPEAKER RETURN CIRCUIT FOR A SHORT CIRCUIT "MASS" |
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1Measure the resistance between the following audio unit connector pins and ground: - (Front left speaker) pin 2 of connector C442, electrical circuit 10-MD10 (gray-black), on the wiring side, and ground. - (Rear left speaker) pin 4 of connector C442, electrical circuit 10-MD11 (gray-white), on the wiring side, and ground. - (Front right speaker) pin 6 of connector C442, electrical circuit 10-MD17 (gray-red), on the wiring side, and ground. - (Rear right speaker) pin 8 of connector C442, electrical circuit 10-MD18 (gray), on the wiring side, and ground. |
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• Is the resistance greater than 10,000 Ohms in all cases? |
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→ Yes |
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INSTALL the new audio unit. CHECK that the system is working properly. |
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→ No |
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REPAIR the electrical circuit concerned. CHECK the system for proper operation. |
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PINPOINT TEST L: NO SOUND IN ONE OR MORE SPEAKERS (NOT ALL SPEAKERS)
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STATES |
DETAILS/RESULTS/ACTIONS |
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L1: CHECKING THE RESISTANCE OF THE SPEAKER CIRCUIT |
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1Disconnect the non-working speaker. |
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2Measure the resistance between pins 1 and 2 of the non-working speaker, on the element side. |
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• Is the resistance approximately 4.0 ohms? |
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→ Yes |
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Go to L2. |
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→ No |
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INSTALL new speaker(s). CHECK system for proper operation. |
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L2: CHECKING THE RESISTANCE OF THE SPEAKER CIRCUIT - WITH THE SPEAKER DISCONNECTED |
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1Disconnect C442 from the audio unit. |
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2Measure the resistance between the pins of the C442 connector of the audio unit and the connector of the non-working speaker(s). - (Front left speaker) pin 1 of connector C442, circuit 8-MD10 (white/black), harness side, and pin 2 of connector C937, circuit 8-MD28 (white), harness side. - (Front left speaker) pin 2 of connector C442, circuit 10-MD10 (gray-black), harness side, and pin 1 of connector C937, circuit 10-MD28 (gray), harness side. - (Front right speaker) pin 5 of connector C442, circuit 8-MD17 (white/red), harness side, and pin 2 of connector C938, circuit 8-MD28 (white), harness side. - (Front right speaker) pin 6 of connector C442, circuit 10-MD17 (gray-red), harness side, and pin 1 of connector C938, circuit 10-MD28 (brown), harness side. - (Rear left speaker) pin 3 of connector C442, circuit 8-MD11 (white/green), harness side, and pin 2 of connector C939, circuit 8-MD29 (white/green), harness side. - (Rear left speaker) pin 4 of connector C442, circuit 10-MD11 (gray/white), harness side, and pin 1 of connector C939, circuit 10-MD11 (gray/white), harness side. - (Rear right speaker) pin 7 of connector C442, circuit 8-MD18 (white), harness side, and pin 2 of connector C940, circuit 8-MD29 (white/green), harness side. - (Rear right speaker) pin 8 of connector C442, circuit 10-MD18 (gray), harness side, and pin 1 of connector C940, circuit 10-MD29 (gray/white), harness side. |
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• Resistance less than 5 ohms? |
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→ Yes |
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INSTALL a new speaker. CHECK the system for proper operation. If the problem persists, INSTALL a new audio unit. CHECK the system for proper operation |
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→ No |
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REPAIR the electrical circuit concerned. CHECK the system for proper operation. |
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