Rear center stop lamp socket

Do you know anything about automotive electronic's ? The brake pedal position sensor is a input to the BCM - body control module ,the BCM turns on the stop lamps . Possible short in the (CHMSL ) - center high mount stop lamps , wiring etc.... Causing problem inside the BCM . Do you know what wiring diagrams are ? Free one's here http://www.bbbind.com/free-tsb Enter vehicle info. year , make , model an engine size . Under system click on lighting , then under subsystem click on exterior lighting . Click the search button then the blue link's . First diagram show's the brake pedal position sensor input to the BCM ,lower right . Second diagram show's BCM power supply to the third brake light (CHMSL) . Having a qualified repair shop with a professional scan tool to check for DTC'S - diagnostic trouble code's could save a bunch of time in diagnosing the problem .
DTC B3903
The body control module (BCM) supplies voltage to the center high mount stop lamp (CHMSL) and the powertrain control module (PCM) when the stop lamps are active.
DTC B3903 Stop Lamp Relay Circuit

Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.

If any light lights up when you apply brakes, then the brake switch is ok. The problem could be a fuse and/or a relay. or the bulbs. Those bulbs are dual filament so one filament could be bad, for stop or tail lights.

have you started with the basics check the fuses the head lights and the parking lights are different fuses

{: ) Check out the ST/LP fuse(25amp) at the underhood fuseblock. Also the VEH STOP (15amp) and VEH CHMSL (10amp) fuses at the fuseblock rear. If the center high mounted stop lamp is also not working, and you can't get any 12volts on either stoplamp bulb sockets, then most likely causes are the fuse, stoplamp switch on the brake pedal, and a faulty wiring.
If the center stop lamp is working and both sides are not, then the trouble can be isolated on the wirings or terminals of the two bulbs on the sides.
Wish you luck.

its the same fuse so i would suspect a problem with either the earth wire on the back or the feed but as this is obviously a american vehicle then the back lights are different to out europeon models ,now i have converted a few american imports to europeon standard with no problem but i have had to disconnect that funny stop light switch affair so perhaps the fault is the switch as it interferes with stop light ,weird system and totally illegal here in europe

Rear Turn Signal, Brake and Parking Lights

1. Remove the tail light assembly screws, then the assembly.
2. Disconnect the twist lock socket from the lens housing. NOTE: To remove the bulb, turn the twist lock socket (at the rear of the housing) counterclockwise 1?4 turn, then remove the socket with the bulb; replace the bulb if defective. Fig. 7: Remove the tail light assembly screws, then the assembly - wagon shown Fig. 8: Twist the socket counterclockwise to remove from the housing Fig. 9: This type of bulb simply can be pulled out of the socket for replacement To install:
   
3. Attach the socket assemblies to the back of the lamp unit.
4. Install the lamp assembly to the vehicle with the mounting screws.

License Plate Light

1. Remove the lens screws.
2. Once the lens is removed you, can access the bulb and replace if needed. To install:
   
3. Install the new bulb, then attach the lens to the body of the vehicle.

Center High Mount Stop Lamp

1. Remove the screws securing the lamp cover.
2. Remove the mounting nuts, then unplug the electrical harness to the lamp assembly.
3. The lamp now should come out. To install:
   
4. Position the lamp assembly to the vehicle, then attach the electrical harness to the lamp.
5. Install the mounting nut, tighten to 62 inch lbs. (7 Nm).
6. Attach the lamp cover. Fig. 10: Exploded view of the center high mount stop lamp assembly - wagon shown
   Fig. 11: Light bulb application chart for all models with non-European headlamps
   Fig. 12: Light bulb application chart for Buicks with European headlamps
   Fig. 13: Light bulb application chart for Oldsmobiles with European headlamps
   

Tail Lamp: Service and Repair
TAIL LAMP REPLACEMENT
REMOVAL PROCEDURE
1. Open the rear compartment lid.
2. Remove the rear compartment trim panel (4).
3. Disconnect the tail lamp electrical connectors.
4. Remove the following components from the vehicle:
- The 3 nuts (3)
- The tail lamp (7)
5. Remove the following from the tail lamp:
- The stop lamp socket (2)
- The turn signal lamp socket (5)
6. Remove the following from the lamp sockets, if necessary:
- The stop lamp bulb (1)
- The turn signal lamp bulb (6)
INSTALLATION PROCEDURE
1. Install the following to the lamp sockets, if removed:
- The stop lamp bulb (1)
- The turn signal lamp bulb (6)
2. Install the following to the tail lamp:
- The stop lamp socket (2)
- The turn signal lamp socket (5)
3. Install the tail lamp (7) to the vehicle. Secure the tail lamp (7) with the 3 nuts (3).
NOTE: Refer to Fastener Notice in Service Precautions.
Tighten the tail lamp nuts to 10 N.m (89 lb in).
4. Connect the tail lamp electrical connectors.
5. Install the rear compartment trim panel (4) to the vehicle.
6. Close the rear compartment lid.

Rear Turn Signal, Brake and Parking Lights


STORM COUPE

1. Disconnect the negative battery cable.
2. Lift the luggage compartment floor carpet toward the front of the vehicle and remove the spare tire cover panel.
3. Remove the ten plastic retaining clips from the rear end trim panel.
4. Disconnect the luggage compartment lamp electrical connector.
5. Remove the luggage compartment trim panel and the rear end trim panel.
6. Disconnect the rear combination lamp assembly electrical connector. Fig. 1: Rear Turn Signal, Brake and Parking Lights — Storm

1. Remove the seven nuts and the rear combination lamp assembly from the vehicle.
2. Disconnect the rear combination lamp electrical connector.
3. Remove the four bulb sockets from the rear combination lamp assembly and remove the four bulbs from the sockets. To install:
   
4. Install the four bulbs to the sockets and install the four bulb sockets to the rear combination lamp assembly.
5. Connect the rear combination lamp electrical connector.
6. Install the rear combination lamp assembly to the vehicle and the seven nuts.
7. Connect the rear combination lamp assembly electrical connector.
8. Install the rear end trim panel and the luggage compartment trim panel.
9. Connect the luggage compartment lamp electrical connector.
10. Install the ten plastic retaining clips to the rear end trim panel.
11. Install the spare tire cover panel and the luggage compartment floor carpet.
12. Connect the negative battery cable.

I have just sent you 4 PDFs via e-mail. They should help you out.

Most of these type lights do not have a plug. I am assuming that you want to replace a burnt out lamp.

Here's what you do. Remove the assembtail lamp assembly. It is usually held on with 2 or 3 phillips head screws. If the problem is a burnt out lamp, the lamp assembly will unscrew from the unit by turning it counterclockwise about a quarter turn. Take the bad bulb to an auto parts store and get a replacement. The bulb will only fit one way into its socket. Then take the socket with the new bulb and insert it back in the housing. Again it will only fit one way. remount the tail light assembly.

If the actual plastic tail light assembly is broken or cracked remove the lamp assembly as described above, take the broken tail light to a dealer and ghet a new one. They are expensive. I just replaced one for my 95 F-150 pickup and it was $40.