NO START HOT OR COLD ENGINE REPLACE STARTER MOTOR

VEHICLES AFFECTED: 1988 C AND K TRUCKS EQUIPPED WITH LB4 4.3L ENGINES

Some 1988 C and K Trucks equipped with LB4 4.3L engines, may experience an intermittent no-start condition on hot or cold engines when equipped with part number 9000719 (OE) or 10465001 (SERVICE) Starting Motors having the following date codes stamped into the Starting Motor CE Frame:

DATE CODE RANGE

7Fl5 THRU 7F30 7GO1 THRU 7G31 7HOl THRU 7H27

(NOTE: lst digit refers to year, 2nd digit refers to month, and last two digits refer to day of manufacture.)

This Starting Motor date code is visible to the Technician without removing the Starting Motor from the vehicle. (Refer to Figure.)

CONDITION: Some vehicles listed above may not start at times because the Starter will not stay engaged and crank the engine. This condition may first occur when the engine is extremely hot or cold, and will be characterized by a chattering or oscillating sound from the Starting Motor. Eventually, the starter may not crank the engine even at mid-range temperatures.

CAUSE: The inability of the Starter to stay engaged and crank the engine may be caused by an intermittent ground connection to the Solenoid Hold-In Coil. The intermittent ground condition is due to a temporary processing change made in solenoid manufacture and is limited to some, but not all, Starting Motors with the above part numbers and date codes. This connection is internal to the solenoid and cannot be checked visually. Because of the intermittent nature, an electrical check of the Hold-In Circuit is not always reliable. This condition must not be confused with a similar condition which may be caused by a discharged battery or a poor electrical connection in the Cranking Circuit.

CORRECTION: If a customer comments on the Starting Motor not staying engaged to crank a hot or cold engine, the usual diagnostic procedure described in the Vehicle Service Manual should be used. Check the Battery to see that it is in a sufficient state of charge, and check the wiring connections to the Battery, Starting Motor, Solenoid, and Ignition Switch to assure that they are clean and tight. If these checks do not reveal any other condition that may have caused the comment, the Starting Motor date code should be checked to see if it falls within the date code range listed above. If it does, the Starting Motor should be replaced.

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.