AM Radio - Static Noise on Weak Stations

Ref: AUDIO

No.: AU001-96

Date: AUGUST 23, 1996

Model: ALL MODELS

Title: STATIC NOISE ON WEAK AM STATIONS

Some Lexus audio systems may exhibit audible electrical noise on weak AM stations when various electrical accessories (turn signals, rear defogger, cruise control, brakes, etc.) are operated.

Poor antenna grounding can cause this condition.

To eliminate or reduce the intensity of the noise use the following repair procedure:

IMPORTANT:
For '92 - '94 SC 300/400, refer to TSIB EL95-006.

REPAIR PROCEDURE:





1. Play the radio on a strong, static-free AM station and slowly move the tip of the antenna mast forward and back approximately 2 inches (Fig. 1). If static noise is not heard, go to Step 2. If static noise is heard during antenna movement, replace the antenna mast and go to Step 3.

NOTE:
Do not touch the antenna mast with your bare hands. Use a glove or nonmetallic object to move the antenna. (If you touch the antenna with your hands, you will change the antenna sensitivity).





2. Remove the antenna mast and inspect the base of the mast for corrosion and damage. Clean with 1500 grit sandpaper (Fig. 2).





3. Remove the antenna assembly and inspect the inner fender around the antenna hole for corrosion. Clean with 1500 grit sandpaper (Fig. 3).





4. Remove the antenna spacer grommet at the top of the antenna assembly and inspect for corrosion. Clean with 1500 grit sandpaper (Fig. 4).





5. Reinstall the antenna assembly. Be sure to install the external antenna nut (escutcheon) first. Then install the nut which holds the assembly to the inner bracket (Fig. 5).





6. Check to make sure that the teeth on the antenna spacer grommet make good contact with the inner fender well (Fig. 6).





7. Inspect antenna cable connection and clean as necessary. Reconnect the antenna cable, the wire harness and the drain hose (Fig. 7).





WARRANTY INFORMATION: