Repair Information for Reconnection of Rear Window Defroster Contact or Tab

This bulletin is being revised to update the part number table and to alter the repair instructions for the new style utility (GMT900) vehicles with moveable glass. Please discard Corporate Bulletin Number 03-08-48-006C (Section 08 - Body and Accessories).

Soldering Defroster Contact Tabs

In most applications it is preferable to create a new solder connection to reattach a separated rear defroster tab. If you take note of the steps below, it is possible to create a new solder joint that is equal to, or stronger than, the original. The generic procedure below is not very time intensive, but does include minor preparation work to create a good bonding surface. Be sure to follow each of the steps as combined they will produce the strongest bond possible. Please consider the following before attempting the repair:

Soldering Procedure

1. In many cases the terminal tab will still be in the connector when you examine the vehicle. For Chevrolet Tahoe, Suburban, GMC Yukon, and Cadillac Escalade vehicles (with moveable glass), always replace the defroster tab (GM P/N 25916031). For all other vehicles, please reconnect the original defroster tab.

Important: DO NOT re-use the existing defroster tab on new style utility (GMT900) vehicles with moveable glass.




2. Prepare the surface of the used defroster tab (Not required for new tabs on new style utility models (GMT 900) and the defroster buss bar with fine grain (500 grit) sandpaper or Emery cloth. It is not necessary to remove all of the original solder but it should be scuffed sufficiently so that no oxidation is present. The photo above shows a close up of a properly prepared surface.

Tip
You may want to mask the glass around the contact area with tape. This is easy to do and will allow you to safely prepare the contact surface without the risk of scratching the glass or the black painted shading.

Important: Most rear glass has a black painted masking around the edge of the glass. When cleaning up the connection surface be very careful not to damage the surface of the black shading or the surface of the glass.




3. Wipe the newly prepared contact area with Kent Automotive Acrysol (or equivalent) to remove any residual oil or dirt.






Important: You must use a Silver-Bearing Solder to make the solder joint. DO NOT attempt this repair with conventional Lead / Tin solders. Most suppliers have this type of solder available, and it is available nationally at Radio Shack. It is sold in several diameters and either are acceptable for this repair.

4. For this step, it is permitted that two technicians be used if required. Heat the new contact on the surface of the buss bar that is to be soldered. Long nose pliers are suggested to hold the contact in place. Keep the solder ready and begin flowing out the solder as soon as the melting temperature has been reached.

Tip
If a single technician is attempting this repair, it is sometimes beneficial to wrap one turn of the solder around the new contacts base. In this manner as the melting point of the solder is reached, a layer is deposited on the bottom side of the contact.

Important: Try to align the new contact so that it is positioned with the same attitude as the original contact.




5. The photo above pictures an ideal finished solder joint. Additional stray solder will not harm the performance of the bond however, while it is unlikely that customers may refer to the appearance of the rear window defroster and its components as a positive styling feature of the vehicle interior, it is easy to elicit the opposite reaction due to a poor cosmetic application.
6. Remove and replace the rear defogger electrical power connector by crimping a new connector to the feed wire. The proper connector can be found in the Packard Electrical Assortment, Tray 18, Position 5. The connector is P/N 12034110.
7. Apply a small amount of GM Vehicle Care Dielectric Lubricant to the rear defogger connector.
8. Connect the electrical connector to the defroster tab. Be sure to fully engage the connector. An improperly seated connector may cause excessive resistance and hamper proper operation of the defroster.

Acrysol can be ordered directly from Kent Automotive at 1-800-654-6333 (in Canada, 1-800-563-1717).

Radio Shack products can be found nationally at retail locations, www.radioshack.com, or at 1-800-843-7422.

In Canada, use The Source by Circuit City -- www.thesourcecc.ca or 1-866-454-4426 (English) or 1-866-544-4431 (French).

The balance of the parts list can be ordered through GMSPO.

For vehicles repaired under warranty, use:

For vehicles repaired under warranty, use: