Headlamps - Will Not Turn Off
File In Section: 8 - Chassis/Body ElectricalBulletin No. 48-81-04
Date: December, 1994
Subject:
Head lamps Will Not Turn Off on Vehicles with Twilight Sentinel (T82) or Daytime Running Lamps (T61), (Open Circuit 120)
Models:
1995 Buick LeSabre VIN Breakpoint: 458120
1995 Buick Park Avenue VIN Breakpoint: 624194
1995 Oldsmobile Eighty Eight VIN Breakpoint: 817950
1995 Oldsmobile Ninety Eight VIN Breakpoint: 310745
1995 Pontiac Bonneville VIN Breakpoint: 237691
Note:
This bulletin does not address the condition of the headlamps remaining on with the Twilight Sentinel enabled, the ignition switch turned "Off" and the vehicle out of "Park". This is covered in Corporate bulletin # 438133.
This bulletin also should not be confused with the condition(s) addressed by Product Campaigns 95-C-04 or 95-C-07 and outlined in upcoming Canadian Campaign # 4D48. However, the procedures in this bulletin should be performed in addition to replacing the lighting control modules affected by the Product Campaigns to insure that the concern has been corrected.
CONDITION
Some owners may comment that the headlamps will not turn off on vehicles equipped with twilight sentinel (T82) or daytime running lamps (T61).
CAUSE
When the ignition switch is cycled off, the fuel pump provides a transient voltage between the fuel pump and the lighting control module. This may cause the headlamps to remain on.
CORRECTION
Wiring Harness:
Reference page 8A-20-10 in the appropriate Service Manual for schematic and included illustration in this bulletin. The following steps should be performed to interrupt the path for the transient between the fuel pump and the lighting control module.
1. Disconnect negative battery cable.
2. Locate circuit 120, the 0.8O mm(2) gray wire located in cavity A5 of connector C260. Reference pages 8A-202-8 and 9 in the appropriate Service Manual.
3. Follow circuit 120 wire back approximately 4 inches under conduit on the C260 branch in the engine compartment.
4. Cut circuit 120 wire approximately 4 inches back under the conduit.
5. Make sure that none of the core is exposed. Both sides of the circuit 120 wire will have B+ on it. Fully insulate both ends of circuit 120 wire to prevent any possibility of either end shorting.
6. Wrap each end of circuit 120 wire with splice tape. Then wrap into harness main with electrical tape.
7. Secure the cut and insulated leads in the wiring bundle.
8. Replace any harness covering that was removed.
9. Reconnect battery and check operation of headlamps.
Warranty Information
For vehicles repaired under warranty, use:
LABOR OPERATION LABOR TIME
T259O 0.3 hr