ELECT. SYSTEM MANUAL UPDATE REVISED PARASITIC DRAIN TEST

SUBJECT: ELECTRICAL SYSTEMS MANUAL UPDATE - REVISED PARASITIC CURRENT DRAIN PROCEDURE

MODELS AFFECTED: 1991 LESABRE AND PARK AVENUE

Please cancel Service Bulletin 91-8-15 dated February, 1991, (Corporation Number 008126) - referencing Parasitic Drain Test.

The following is a revised Parasitic Current Drain Procedure for (Test A) found in LeSabre Electrical Systems Manual - page 44, and Park Avenue/Ultra Electrical Systems Manual - page 50.

Please update your service manual accordingly.

PARASITIC CURRENT DRAIN PROCEDURE

Tools needed - J 38758 Parasitic Draw Test Switch - Ammeter with at least 10 amp measurement capabilites

NOTICE: The parasitic draw test switch should never be turned to the "OFF" position with the engine running or damage could occur to the attached ammeter or the vehicle electrical system.

1. Remove battery cable from battery negative terminal. 2. Install the parasitic draw test switch male end to negative battery cable. 3. Turn test switch knob to the "OFF" position. 4. Install negative battery cable to female end of the test switch tool. 5. Turn the test switch tool knob to the "ON" position. 6. Road test vehicle while activating all accessories (radio, A/C, etc.) 7. Turn ignition switch to the "Locked" position and remove ignition key. 8. Set ammeter to the 10 amp scale and connect to terminals on test switch tool. 9. Turn test switch tool knob to the " OFF" position to allow current to flow through the ammeter. 10. Check current reading. If current reading is at or below two amps, turn the test tool knob to the "ON" position (to maintain continuity in the electrical system) and switch down to the two amp scale for a more accurate reading when draw test tool knob is turned "OFF". If current reading is above two amps, follow Parasitic Drain Chart for specific current loads.

IMPORTANT: Always turn the test switch tool knob to the "ON" position before removing each fuse to maintain continuity in the electrical system and to avoid damaging the ammeter due to accidental over loading (i.e. opening door to change fuse, etc.)

11. If current draw is above specifications listed in the Parasitic Drain Chart, remove system fuses one fuse at a time until the current draw returns to a value less than or equal to the specifications listed. Perform steps 8 through 10 each time a fuse is removed. Refer to the applicable 1991 Buick Electrical Systems Manual for specific circuit schematics. 12. When cause of excessive current drain has been located and repaired, remove current draw test tool and connect negative battery cable to negative battery terminal.

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.