Radio Static With Rear Defogger On or Inoperative Grid PIC4180

Title:2008/07/28 Radio Static With Rear Defogger On or Inoperative Grid PIC4180

Date:	07/28/2008
To:	Service Department
From:	Technical Assistance

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Subject:
Radio Static With Rear Defogger On or Inoperative Grid PIC4180
Models:
All Saab Models

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

CONDITION/CONCERN:

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. 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.

RECOMMENDATION/INSTRUCTIONS:

To perform the diagnosis and repair procedure you will need:
- Permatex Quick Grid, DuPont 4817, GM P /N 12346001 or equivalent
- A small ball of fine steel wool Type 00 (available in most hardware stores)

Correction

To detect a broken grid line and to isolate the exact location of the break, perform the following:

Caution:
o Approved safety glasses and gloves should be worn when performing this procedure to reduce the chance of personal injury.
o Cover the rear shelf area to prevent damage to the interior trim material.

1. Start the engine and turn on the back window defogger. (Insure proper ventilation for exhaust)

2. 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 grid line and move it to the opposite side of the grid line. When you bridge the grid line break with the steel wool, you will see a small spark. Having an assistant cover the windows with blankets may help make the spark easier to see. If the vehicle also has a radio static concern, a change in the static level will be heard when the gap is bridged. 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 grid line. Close visual inspection using a magnifying glass may be the only way to locate breaks in this case.

3. Use Permatex Quick Grid, DuPont 4817, GM P/N 12346001, or equivalent, to repair each broken grid line. Follow the manufacturer's instructions.

4. Recheck the grid line with heat sensitive paper or a portable infrared thermometer to ensure that the line is now functional and that the repair was successful.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.