Lighting - Headlight Dimming/Engine Surge/Hesitation

88chevy06

GMC NUMBER: 88-T-94


GROUP: 6D-Engine Electrical

DATE: March, 1988

CORPORATE
NUMBER: 866406
SUBJECT: MOMENTARY HEADLIGHT DIMMING AND/OR ENGINE SURGE, HESITATION

MODELS: 1988 C/K TRUCKS WITH 100 AMP ALTERNATOR (K60)
1988 C/K model trucks equipped with a 100 amp alternator, service P/N 10463045 (OE P/N 1105711), may experience a momentary alternator voltage drop. The voltage drop may occur at night on deceleration toward a stop and could be manifested by any or all of the following symptoms:

1. Momentary head light dim.

2. Momentary voltmeter needle fluctuation.

3. Momentary slowing of blower motor.
4. Momentary engine stumble, slight surge or hesistation.

FIGURE 1:

The integral regulator in the alternator has been changed in current production to address this condition. There is no part number change. The new alternator can be identified by a date code 2018, or greater, stamped on the bottom boss below the part number (see Figure No. 1). The alternator is not serviceable and must be replaced as an assembly. Parts ordered from GMSPO will be the new ones discussed above.