A amplifier is built into the manual antenna.
1. Turn on the audio unit and radio, and measure the voltage at manual antenna connector terminal C.
If the voltage is B+, go to the next step.
If the voltage is not B+, inspect the audio unit or the antenna feeder.
1. Remove the battery cover.
2. Disconnect the negative battery cable. (SeeBATTERY REMOVAL/INSTALLATION [LF].)
3. Disconnect the manual antenna connector.
4. Inspect for continuity between the manual antenna terminals using an ohmmeter.
If not as specified, replace the manual antenna.