For 1990-2009 cars

• | The electronically tuned radio receives power from the RADIO fuse and CKT 43. The radio receives power when the ignition switch is in RUN or ACCY.

• | The clock and memory circuits receive power from the Multi-Function Alarm Module's Parasitic Power Control. The circuits receive power through CKT 1733 at all times.

• | The radio is grounded through CKT 350.

• | When the ignition switch is in RUN or ACCY, the vacuum fluorescent display illuminates. The display shows the time or radio frequency setting.

• | The radio illumination is controlled by the instrument panel lamp dimmer.

• | When the headlamp switch is in PARK or HEAD, voltage is applied through the dimmer control and CKT 8 to the radio panel light and the internal circuitry.

• | When the headlamp switch is in PARK or HEAD, voltage is applied through CKT 9 to the radio. The voltage signals the internal circuitry to adjust the brightness of the vacuum fluorescent display to a level determined by the voltage of CKT 8.

Important: Electromagnetic Interference (EMI) may cause a fewer number of stations to be received in 1 of the 3 modes. The EMI may be caused by various vehicle components. This may be the cause of the differences in reception. Inspect for components powered up in the 3 various key positions. This may eliminate the following conditions:

• | Engine running components

• | Ignition on components

For example, if the same number of stations are received with the engine running as when the engine was off, the components active with the engine running are not causing the interference.