GM Service Manual Online
For 1990-2009 cars
Makes 🢒 Chevrolet 🢒 2004 🢒 C-Series Medium Duty Truck C6/7/8 - Mexico 🢒 Body 🢒 Lighting Systems 🢒 Backup Lamp Switch Replacement

Removal Procedure

    Object Number: 790997 Size: SH
  1. Raise and suitably support the vehicle, if required. Refer to Lifting and Jacking the Vehicle in General Information.
  2. If equipped with the Eaton Fuller® RT6609 9 speed transmission, disconnect the backup lamp switch electrical connector (2).

    3. Object Number: 791220 Size: SH
  3. If equipped with the Spicer® ES52-7B or ES066-7B 7 speed transmissions, disconnect the backup lamp switch electrical connector (2).

    4. Object Number: 791222 Size: SH
  4. If equipped with the Eaton Fuller® RT8709 9 speed, or RT8908LL 10 speed transmissions, disconnect the backup lamp switch electrical connector (1).

    5. Object Number: 791223 Size: SH
  5. If equipped with one of the following Eaton Fuller® transmissions, disconnect the backup lamp switch electrical connector (1, 2).
    6. • 5 speed:
       - FS-4205A/B
       - FS-5205A/B
       - FS-6305A/B
    • 6 speed:
       - FS-5406A
       - FS-6406A
       - FSO-8406A

    Object Number: 791221 Size: SH
  6. If equipped with the Eaton Fuller® FO 8406A-ASX transmission, disconnect the backup lamp switch electrical connector (1).
  7. Remove the backup lamp switch.

Installation Procedure

Important: A NEW backup lamp switch has pre-applied thread sealant on the threads.


    Object Number: 791221 Size: SH
  1. If installing the old backup lamp switch, apply thread sealant GM P/N 12346004 or equivalent to the threads.

    2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Install the backup lamp switch.

    3. Tighten
    Tighten the backup lamp switch to 48 N·m (35 lb ft).

  3. If equipped with the Eaton Fuller® FO 8406A-ASX transmission, connect the backup lamp switch electrical connector (1).

    4. Object Number: 791223 Size: SH
  4. If equipped with one of the following Eaton Fuller® transmissions, connect the backup lamp switch electrical connector (1, 2).
    5. • 5 speed:
       - FS-4205A/B
       - FS-5205A/B
       - FS-6305A/B
    • 6 speed:
       - FS-5406A
       - FS-6406A
       - FSO-8406A

    Object Number: 791222 Size: SH
  5. If equipped with the Eaton Fuller® RT8709 9 speed, or RT8908LL 10 speed transmissions, connect the backup lamp switch electrical connector (1).

    6. Object Number: 791220 Size: SH
  6. If equipped with the Spicer® ES52-7B or ES066-7B 7 speed transmissions, connect the backup lamp switch electrical connector (2).

    7. Object Number: 790997 Size: SH
  7. If equipped with the Eaton® Fuller® RT6609 9 speed transmission, connect the backup lamp switch electrical connector (2).
  8. Lower the vehicle, if required.