weephee Posted December 3, 2006 Report Share Posted December 3, 2006 Just wondering if anyone has experienced this problem. The radio is working fine but when I push the rear defog button the radio signal is greatly diminished thereby causing a lot of static. This is on a 2002 STS. Thank for any info Link to comment Share on other sites More sharing options...
chazglenn3 Posted December 3, 2006 Report Share Posted December 3, 2006 Sounds like there may be a loose connection on the antenna box above the headliner at the top of the rear window. That is just a WAG, though. There are antenna wires and defroster lines in the rear window, but I'm not sure how they could interfere with each other. Charles Charles Link to comment Share on other sites More sharing options...
WarrenJ Posted December 3, 2006 Report Share Posted December 3, 2006 Just something to look at . . . . . . Regards, Warren *********************************** Document ID# 1583196 2002 Cadillac Seville -------------------------------------------------------------------------------- Poor Radio Reception or Radio Static/Increased Interference with Rear Window Defogger On or Some Rear Window Defogger Grids may be Inoperative (Diagnose and Repair Rear Window Defogger Heating Grid) #03-08-44-005C - (Jan 19, 2005) Poor Radio Reception or Radio Static/Increased Interference with Rear Window Defogger On or Some Rear Window Defogger Grids May Be Inoperative (Diagnose and Repair Rear Window Defogger Heating Grid) 1997-2005 Buick Century, LeSabre, Park Avenue, Regal 1997-2001 Cadillac Catera 1997-2002 Cadillac Eldorado 1997-2004 Cadillac Seville 1997-2005 Cadillac DeVille 2003-2005 Cadillac CTS 1997-2005 Chevrolet Corvette 2000-2005 Chevrolet Impala, Monte Carlo 2004-2005 Chevrolet Epica, Malibu 1997-2003 Oldsmobile Aurora 1998-2002 Oldsmobile Intrigue 1999-2004 Oldsmobile Alero 1997-2005 Pontiac Grand Am, Grand Prix 2004-2005 Pontiac GTO This bulletin is being revised to add the 2005 model year and update the part number information for Permatex Quick Grid. Please discard Corporate Bulletin Number 03-08-44-005B (Section 08 -- Body and Accessories). Condition Some customers may comment that the radio has poor reception or radio static/increased interference when the rear window defogger is turned on. Also, some rear window defogger grids may be inoperative. Cause This condition may be due to microscopic cracks in the electrically heated grids of the rear window defogger. These cracks may cause electrical interference when the rear defogger is on and this could affect radio reception. Background The addition of vertical grid lines to the heated back window defogger circuits has made it difficult to detect broken defogger grid lines. In the past, it was a simple matter to use a voltmeter to check the continuity of each grid line in order to locate a non-functional line. New design back windows have two vertical grid lines that connect all of the horizontal grid lines together, thereby providing alternate routes for the electrical current to follow. This makes the old test method ineffective. Materials Required • Permatex Quick Grid, GM P/N 12346001, or equivalent • A small ball of fine steel wool Type 00, or • Optional -- A strip of liquid crystal heat sensitive paper, 51 mm x 305 mm (2 in x 12 in) or similar size (Contact Edmund Scientific at 800-728-6999 for part number CR30723-70 or go to www.scientificsonline.com), or • Optional -- A portable infrared thermometer, GE-46819, available from Kent-Moore (1-800-345-2233), or equivalent. Correction There are three distinct zones across the back window that must be checked. They are: • the driver's side outboard of the two vertical lines • the passenger side outboard of the two vertical lines • the central zone that falls between the two vertical lines To detect a broken grid line in any of the above three zones and to isolate the exact location of the break, perform the following: Caution: • Approved safety glasses and gloves should be worn when performing this procedure to reduce the chance of personal injury. • Cover the rear shelf area to prevent damage to the interior trim material. Start the engine and turn on the back window defogger. Important: The first place to check should be the driver side segment 2 to 3 lines up from the bottom about 380-385 mm (15-15.2 in) from the buss bar. Take the ball of fine steel wool and twist one end to a point. Move the point slowly across each grid line. Be sure to start at the far side of the zone and move it to the opposite side of the zone. When you bridge the grid line break with the steel wool, you will see a small spark. Repeat the test over the same area to be sure you have accurately located the break. Mark the exact location of the grid line break. Repeat this portion of the test for each grid line. If you do not see a spark at any point, it is possible that there are two breaks in the same line and zone. Close visual inspection using a magnifying glass may be the only way to locate breaks in this case. The following are provided as a alternative way to detect a non-functional grid line. If available, use in addition to the steel wool. Method using liquid crystal heat sensitive paper. Important: The first part of the test must be completed quickly before the entire surface of the back window becomes warm. From outside the vehicle, place the heat sensitive paper (dull surface in contact with the glass) against the top driver side grid line. Start the engine and turn on the back window defogger. A distinct color change will take place at each conductive grid line. Repeat for the bottom grid lines until they have all been checked in the driver side zone. Repeat the process for the passenger side and center area zones. If no color change is noted for a grid line, place a crayon or china marker check mark beside it. Mark each grid line in the zone where it is non-conductive and therefore not heating up. More than one broken grid line may be found. Method using a portable infrared thermometer. Start the engine and turn on the rear back window defogger. From inside the vehicle, start at the top driver side grid line and slowly run the portable infrared thermometer vertically down the rear window contacting each grid line. You should be able to see a district variation in temperature readings. Mark each grid line in the zone where it is non-conductive and, therefore, not heating up. More than one broken grid line may be found. Repeat the process for the passenger side and center area zones. Use Permatex Quick Grid, GM P/N 12346001, or equivalent, to repair each broken grid line. Follow the manufacturer's instructions. Wait 24 hours before turning the defogger on, or the repair can be fast cured using a heat gun, 260°C -- 371°C (500°F -- 700°F). Hold the heat gun within 25 - 51 mm (1- 2 in) from the repair point for 2 to 3 minutes. Recheck the grid line with the heat sensitive paper or a portable infrared thermometer to ensure that the line is now functional and that the repair was successful. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C0631 Grid, Electric Back Window Defogger -- Repair 0.3 hr Add To Repair Each Additional Grid 0.1 hr Add Diagnosis Time 0-0.3 hr GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION © Copyright General Motors Corporation. All Rights Reserved. -------------------------------------------------------------------------------- There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
chazglenn3 Posted December 3, 2006 Report Share Posted December 3, 2006 GREAT post, Warren! (Where do you get these bulletins) The right third of my grid is inop, and now I know that the three sections are independent, and where to look for the break in the grid lines. Of course to do this would require the removal of my window tint, so this may not happen in the immediate future, but will print this for reference. Charles Charles Link to comment Share on other sites More sharing options...
weephee Posted December 3, 2006 Author Report Share Posted December 3, 2006 Thanks to all how responded and a special thanks to Warren for all this information. I will try it out in the next week and let you know the results. Thanks again. Link to comment Share on other sites More sharing options...
weephee Posted December 16, 2006 Author Report Share Posted December 16, 2006 We finally have a nice day here and I was able to go out and check the grid using the fine steel wool. It worked exactly as per the bulletin. I found the break in no time and as soon as the steel wool shorted across the opening the radio static quit. Thanks again Warren for your information Link to comment Share on other sites More sharing options...
WarrenJ Posted December 16, 2006 Report Share Posted December 16, 2006 We finally have a nice day here and I was able to go out and check the grid using the fine steel wool. It worked exactly as per the bulletin. I found the break in no time and as soon as the steel wool shorted across the opening the radio static quit. Thanks again Warren for your information That's great! Glad to hear of your success. And glad to see you posted back. Too often we never learn the end game and don't benefit from that knowledge. Thanks, Warren There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
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