GLOW PLUG INHIBIT SWITCH INSTALLATION PROCEDURE

Model and Year 1984 "C/K/G/P/D" TRUCKS WITH 6.2L DIESEL ENGINE

DIAGNOSIS OF SWITCH

The following procedure is provided for proper diagnosis of the glow plug inhibit switch.

1. Run engine for approximately fifteen (15) minutes to warm engine.

2. With the engine not running and coolant temperature above 52 DEG C (125 DEG F), disconnect plug from inhibitor switch terminals.

3. Use ohm-meter on lowest scale to check for an open circuit. A self-powered test light may also be used. Test across terminals, then from each terminal to ground.

4. If the switch is closed or grounded (test light on or low ohm reading on meter), the switch is faulty. If switch is open and not grounded (test light off or high reading on meter), the switch is functioning properly.

INSTALLATION OF SWITCH

The inhibit switch can be damaged easily during installation. DO NOT use an open-end wrench to install this switch. A socket should be used. The inhibit switch can fail from being installed with too high of a torque. Use 19 to 27 N.m (13 to 20 ft. lbs.) torque when installing this switch. DO NOT OVERTORQUE.

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.