GM Service Manual Online
For 1990-2009 cars only

DIESEL WAIT LIGHT COMES ON CAUSE AND CONDITION

IF THE DIESEL WAIT LIGHT COMES ON AFTER START UP ON 1980-81 CUTLASS MODELS AND PRELIMINARY DIAGNOSIS SHOWS THAT THIS CONDITION IS NOT DUE TO A BAD GLOW PLUG, THE ALTERNATOR DIODE TRIO SHOULD BE CHECKED AS OUTLINED IN THE CHASSIS SERVICE MANUAL. AN INOPERATIVE DIODE TRIO CAN CAUSE THIS CONDITION TO OCCUR, AND NOT NECESSARILY ILLUMINATE THE "CHARGE" LIGHT WARNING INDICATOR.

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.