DEAD BATTERY OR BATTERY DRAIN FROM TOP PULLDOWN MOTOR-REPAIR

SUBJECT: DEAD BATTERY OR BATTERY DRAIN FROM TOP PULLDOWN MOTOR (DIAGNOSIS AND REPAIR PROCEDURES)

VEHICLES AFFECTED: 1987-93 CADILLAC ALLANTE

Some 1987-1993 Allantes may experience a dead battery or battery drain caused by a malfunctioning top pulldown unit. The pulldown unit may cycle up and down continuously after the soft top rear bow is latched or the pulldown unit may not shut off electrically at the bottom of its travel. In either case, the following procedure will correct the condition.

NOTE: Always perform all eight steps even if you find a problem during a particular step.

1. Unlatch the rear of the soft top and open the stowage cover. Verify the metal extension arm on the hook position switch (refer to Figure 1) is free to move and not physically distorted 6r damaged. If distorted or damaged, repair or replace as necessary. Proceed to next step.

NOTE: A distorted or damaged extension arm indicates excessive force has been used in latching the rear bow. To prevent recurrence, ensure that the soft top hook and pulldown unit jaws are properly aligned and operating correctly. Check the main and emergency release cables (refer to Figure 1) for binding/misadjustment which may hold the jaws slightly open and not able to fully grasp the hook. Also, make sure the hook does not contact the pulldown unit when raising or lowering the soft top. Also make sure the customer understands the correct procedure for raising the top before returning the vehicle.

2. Cycle the pulldown unit downward using the rocker switch behind the driver's seat. As the unit is traveling downward, manually depress the extension arm on the hook position switch and check if the pulldown unit stops when it reaches the bottom of its travel. If the unit does not stop, replace the pulldown unit (P/N 3526879 for 1987-1992 models and P/N 3537915 for 1993 models) for an internally shorted switch. Proceed to next step.

3. With the stowage cover in the raised position and the pulldown unit at the top of its travel, lower and latch the soft top rear bow into the pulldown unit. From inside the car observe pulldown unit operation and check how the soft top hook contacts the metal extension arm on the hook position switch. The bottom of the hook should overlap and solidly contact the top surface of the metal extension arm. If the hook passes in front of or slips off of the extension arm, release the hook and reform the extension arm slightly forward and recheck contact. Proceed to next step when proper contact is achieved.

4. If the pulldown unit continues to cycle but hook to metal extension arm contact is good, reform the metal extension arm slightly upward and try latching the top again. Repeat the reforming operation as necessary until the pulldown unit will stop at the bottom of its travel. Proceed to next step.

5. Cycle the soft top rear bow (unlatch and latch) and listen for the audible "snap" of the "T" lever switch as the pulldown reaches the bottom of its travel (refer to Figure 1). If the "snap" is heard proceed to step 8. If the "snap" is not heard proceed to step 6.

6. Remove the pulldown from the rear of the stowage well but do not detach the cables. Disconnect the electrical connection and remove the hook position switch assembly from the pulldown unit. Modify the "T" lever on the switch as shown in Figure 2. Proceed to next step.

NOTE: The reason for this modification is to provide adequate clearance from the "T" lever to the pulldown unit shaft. Without clearance the "T" lever may bind on the pulldown shaft before it completely switches to its full down position. The pulldown motor will not electrically shut off at the bottom of travel if the "T" lever does not completely switch down.

7. Reinstall the soft top hook position switch on the pulldown unit and reinstall the pulldown unit in the stowage well. Latch the soft top and check operation. The audible snap of the "T" lever switching downward should be heard, and the pulldown unit should stop at the bottom of its travel. Proceed to next step.

8. Recheck for a battery drain. If the pulldown unit continues to drain the battery even with the "T" lever operating correctly, then replace the pulldown unit for an internal short.

For vehicles repaired under warranty use:

Labor Time: 0.6 hour.

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.