Inspection
| Symptom | Repair order |
|---|---|
| No power coming in. (No display and no sound from speakers) | Check the fuse and power supply for audio. Check the audio ground. Remove the audio and repair it. |
| A specific speaker does not operate. | Check the speaker. Check the output circuit between audio and speaker. |
| Audio generates noise with engine running. | Check the audio ground. Check the generator. Check the ignition coil. Remove the audio and repair it. |
| AM and FM modes are weak or noisy. | Check the antenna. Check the antenna amplifier. Check the noise suppressor. Check the audio ground. Remove the audio and repair it. |
SYMPTOM REPAIR ORDER DESCRIPTION
Measure the resistance between antenna terminal and each antenna wire.
If an antenna wire is OK, resistance will be less than 1 O. If an antenna wire is broken, the resistance will be more than 1 MO.
Note. When checking the continuity, wind a piece of aluminum foil around the tip of tester probe, and then press the aluminum foil against wire with your finger.
Scheme 1
- Tester probe
- Aluminum foil
- Antenna wire
To locate the broken point, move the probe along antenna wire.
Scheme 2
Measure the antenna amplifier resistance.
Scheme 3
| Terminal No. | Standard |
|---|---|
| 1-a and Amplifier body | More than 100 kO |
| 1-b and Amplifier body | Less than 1 O |
| 2-a and Amplifier body | More than 100 kO |
| 3 and Amplifier body | More than 100 kO |
| 4-a and Amplifier body | More than 100 kO |
| 4-b and Amplifier body | Less than 1 O |
ANTENNA AMPLIFIER RESISTANCE SPECIFICATIONS