DIESEL GLOW PLUG CONTROLLER CONTAMINATION INFORMATION

On early 1982 production vehicles, the engine wiring harness connector at the glow plug controller has an open hole at the #2 pin connection. Moisture and/or dirt entering this hole can cause deterioration of the pin connections and result in a controller malfunction (Figure 1).

If a comment such as poor starting, burned glow plugs, etc. is received, remove the connector from the controller. Check for moisture and dirt. Clean the pin area in the controller and the connector. Reinstall the connector.

Apply a small amount of RTV or similiar silicone sealant over the #2 pin hole to prevent water from entering.

If the controller cycles normally, replacement is not necessary. However, if corrosion of the pins was excessive and/ or the controller does not cycle correctly, it should be changed.

The two (2) wires from #5 and #6 pin position are ground wires. The ground connection is at the rear of the right hand head on a stud which also grounds the body ground strap. (The stud is on the opposite side of the engine from the controller.) Make sure the ground connection is secure (Figure 2).

Use applicable labor operation.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.