Drop down the tailgate and you will find two torx head screws. Remove the screws and from the screw side of the light assembly, turn the light assembly outward from the truck bed. Be careful not to break off the two ears opposite of the screw side, this is why you must turn it outward from the truck bed to remove the light assembly. This will expose the tail light sockets.
BEHIND THE BRAKE PEDAL
How do you replace a break light switch on 1995 Chevy Tahoe
Its the steering colum
This will depend 100% on what tail lights are installed in you Step Van, Chevy did not make the body, many other companies did. So who built your body?
Your brake light is probably brake fluid low or emergency brake on. Rear brake lights are replaced by removing the lens and replacing the dual filament bulb.
Check the fuse, check the bulbs and check the brake light switch, it should be one of those.
burned out bulb, blown fuse, wiring
Usually at the base of the brake pedal.
buy a tap and die set.
Rear loom ground not contacting. Bulbs burned out or missing. Brake light switch or connection to it is fubared.
either dimmer switch or blown fuse If you are saying that the tail brake lights are working but the third brake light is not....It may be a defective turn signal switch in the steering column.
THAT IS USUALLY AN INDICATION OF A BURNED BRAKE LIGHT SWITCH. SWITCH IS USUALLY LOCATED ON THE BRAKE PEDAL ITSELF. DISCONECTED AND IF THE LIGHTS GO OUT YOU HAVE FOUND YOUR PROBLEM , SIMPLY REPLACE IT.