Audio System - AM Band Noise/Poor Reception
Bulletin No.: 06-08-44-024Date: July 21, 2006
TECHNICAL
Subject:
AM Radio Noise Or Poor Reception Induced By Accessories Plugged Into Auxiliary Power Outlet (Install Noise Suppression Filter)
Models:
2003-2007 Chevrolet Express Vans
2003-2007 GMC Savana Vans
Condition
Some customers may comment on a radio noise or poor reception in the AM band when accessories are plugged into the auxiliary power outlet. The noise may be described as a "popping" or "static" and may only be noticeable when the vehicle enters a poor AM reception area, such as beneath an underpass or in a concrete structure.
Cause
This condition may be caused by some cell phone battery chargers that do not meet Federal Communications Commission (FCC) specifications. These accessories may not have electrical noise suppression built-in. This condition may be induced through the battery power feed of the auxiliary power outlet that powers accessories like a cell phone charger.
Correction
Verify that the condition is caused by the use of a customer's accessory plugged into the auxiliary power outlet. To diagnose this condition, move the vehicle to a poor AM reception area (such as inside the shop), or choose a weak AM radio station for testing and connect the customer's accessory that causes the condition. The radio noise will be present with the key in RUN, ACCY, or when RAP is energized.
To repair this condition, technicians are to install a noise suppression filter, P/N 1224205, in the battery positive voltage supply wire to the radio. Use the following procedure to install the noise suppression filter:
1. Remove the radio from it's mounting in the instrument panel so that the wiring harnesses to the radio can be accessed. Refer to the Radio Replacement procedure in SI.
2. Locate the Battery Positive Voltage Supply wire, circuit 340, to the radio. The wire is red/white stripe and is located in cavity B1 of connector C1 (C1 is gray in color with 24 cavities). Refer to the Entertainment Connector End Views in SI for more information.
Important:
The noise suppression filter must be installed as described in the directions included with the filter. The side of the filter with the black ground wire coming out of it must be orientated toward the radio. Ground the black wire of the filter to the chassis of the radio.
3. Install the noise suppression filter, P/N 1224205, following the directions included with the part. Tape the filter to the radio harness to prevent rattles.
4. Install the radio.
5. Reset the clock.
6. Verify that the noise condition has been eliminated and that the radio operates properly.
Parts Information
Warranty Information
For vehicles repaired under warranty, use the table.
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