VOLTAGE REGULATOR FAILURE NO OR FULL CHARGE CONDITION

VEHICLES AFFECTED: 1986 AND 1987 'B', 'G' AND 'F' SERIES VEHICLES

CONDITION: Under certain operating conditions, the voltage regulator may become inoperative causing either a no-charge or full-charge condition. A no-charge can lead to a no-start condition, while a full-charge can lead to excessive battery charging, which can damage the battery.

CORRECTION: An improved voltage regulator, P/N 1116423, has been released. Replace the original regulator with the new regulator. The new regulator can be used for any 1986 B, F or G series or 1987 B or G series, except the 120AMP used on Chevrolet police and taxi option only.

If the entire generator must be replaced, use the table below for correct part numbers.

* Engine Usage Rating Series Original P/N Service P/N ------ ----- ------ ------ ------------- ----------- LGB O 78 12SI 1105565 1101324 LV2 B/O 78 12SI 1105565 " B/O 78 12SI 1105567 " B 94 12SI 1105493 " LG4 C/P/B/O 56 12SI 1105676 1101307 C/P 66 12SI 1105675 " C/P/B/O 78 12SI 1105652 " B/P 94 12SI 1105654 1101308 LD5 C/P/B/O 56 12SI 1100239 1101307 C/P/B/O 78 12SI 1100200 " B 94 12SI 1105444 1101308 C/P/B/O 70 15SI 1105197 1101322 B/P 85 15SI 1105548 1101323

* Engine Usage Rating Series Original P/N Service P/N ------ ----- ------ ------ ------------ ----------- LB4 C/P 56 12SI 1105673 1101307 C/P 66 12SI 1105674 " C/P 78 12SI 1105650 " C/P 94 12SI 1105651 1101308 C 108 17SI 1105639 1101306 LB8 C/P 66 12SI 1105600 1101307 C/P 78 12SI 1105588 " C/P 97 17SI 1105587 1101306 L69 C/P 56 12SI 1105676 1101307 C/P 78 12SI 1105652 " C/P 108 17SI 1101224 1101306

Warranty Information: Use existing Labour operations.

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.