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SERIES 638 GLOW PLUG HARNESS

The glow plug harness is a device which delivers electrical current to the glow plugs to enhance cold weather starting. ‪

Replacement of Glow Plug Harness

To determine if replacement of the glow plug harness is necessary, perform the following procedure. See Figure 28574 . ‪

Note: The glow plug harness is a non-serviceable component and is replaced as a unit. No adjustment is required.

Flowchart for Replacement of Glow Plug Harness

Removal of Glow Plug Harness

Remove glow plug harness as follows: ‪

  1. Disconnect glow plug connectors from glow plugs. See Figure 27771 .

    1.Glow Plug ‪

    2.Glow Plug Harness ‪

    Glow Plug Harness and Glow Plug Location

  2. Disconnect glow plug harness from glow plug relay.
Inspection of Glow Plug Harness

Inspect glow plug harness as follows: ‪

  1. Visually inspect the harness for breaks, cuts, and bare wire.
    1. If the glow plug harness has been damaged, replace the component. Refer to section .
    2. If the glow plug harness has not been damaged, reuse the component. Refer to section .

Installation of Glow Plug Harness

Install glow plug harness as follows: ‪

  1. Connect glow plug harness to the glow plug relay.
  2. Connect glow plug harness to glow plugs.
  3. Run the engine to verify repair.