GM Service Manual Online
For 1990-2009 cars only

Glow Plug Relay Replacement EFI/MFIFederal

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Remove the negative battery cables.

  2. Object Number: 26780  Size: SH
  3. Release the wiring harness connector at the glow plug relay.
  4. Remove the glow plug wiring harness nuts and harness.

  5. Object Number: 26781  Size: SH
  6. Remove the relay mounting nuts.

  7. Object Number: 26782  Size: SH
  8. Remove the glow plug relay by lifting it off the the mounting studs.

Installation Procedure


    Object Number: 26782  Size: SH
  1. Install the glow plug relay on the mounting studs.

  2. Object Number: 26781  Size: SH

    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.

  3. Install the glow plug relay mounting nuts.
  4. Tighten
    Tighten the nuts to 42 N·m (31 lb ft).


    Object Number: 26780  Size: SH
  5. Install the wiring harness connector to the relay.
  6. Install the glow plug wiring harness and nuts.
  7. Tighten
    Tighten the nuts to 5 N·m (44 lb in).

  8. Install the negative battery cables.

Glow Plug Relay Replacement California

Removal Procedure

  1. Remove the negative battery cables.
  2. Remove the upper intake manifold cover by loosening the mounting bolts.

  3. Object Number: 365417  Size: SH
  4. Release all three wiring harness connectors at the glow plug relay.
  5. Remove the glow plug battery feed nut and wire.

  6. Object Number: 365439  Size: SH
  7. Remove the relay mounting bolt.
  8. Remove the glow plug relay.

Installation Procedure


    Object Number: 365439  Size: SH
  1. Install the glow plug relay on the mounting bracket.
  2. Install the glow plug relay mounting bolt.
  3. Tighten
    Tighten the mounting bolt to 22 N·m (16 lb ft).


    Object Number: 365417  Size: SH
  4. Install all three wiring harness connectors to the relay.
  5. Install the glow plug battery feed nut and wire.
  6. Tighten
    Tighten the nut to 4.5 N·m (40 lb in).

  7. Install the upper intake manifold cover.
  8. Tighten
    Tighten the upper intake manifold cover bolts to 11 N·m (100 lb in).

  9. Install the negative battery cables.