The BOO (Brake On/Off) Switch may need to be replaced. If it is bad, it would cause the brake lights to NOT illuminate when the brake pedal is applied.
Check the brake light bulbs, Check the brake light fuse, Check the brake light switch, In that order.
Check your brake light switch at hte brake pedal.
I tried all the fuses, the parts that under the brakes I checked that. All lights come on and working except the brake lights no break lights.
Possible bad switch on the brake pedal? When you push on the brake pedal, it activates a switch, that switch turns on your brake lights. If the bulbs and fuses are ok, check the switch with an ohmeter.
Nonfunctional LightsI'm not familiar with your 2002 Gran Prix, but the problem you describe is universal to all vehicles.The fact that the "third" brake light [in the rear window package tray] IS WORKING, indicates that the brake light switch IS WORKING properly!!!!!That suggests that the reason that the other two brake lights are not working is that there is an "open" condition in the wiring circuit to the other two brake lights. This is confirmed by the fact you replaced the lamps [bulbs] in those other lamp holders with known good lamps.There could be several causes for an open circuit, but the most common include:One of the connector plugs in the wiring harness to the brake lights has become disconnected, orCorrosion has built up inside of one of the connectors [one that feeds both brake lights, which will be in the circuit "ahead" [upstream] of where the wiring harness "splits" off between the two brake lights].Very remote is the possibility that the ground wires on both light assemblies has been disconnected, cut, or corroded.
I just had my Daewoo Leganza brake light switch replaced. It goes under the brake pedal. and now my brake lights work fine.
for the tail lights all the other lights are working blanking lights brake lights and reverse lights but no tail lights on both side
Brake lights often use a dual-filament bulb. If this gets inserted the wrong way other functions can suffer.
blubs blown? Check the turn signal switch.
possibly the fuse for brake lights......also could be brake light switch----turn signal switch----broken wiring anywhere in the vehicle---relay not working ---any other item specific to your venicle.
Blown fuse, both lights are burnt out, There is a wiring or ground issue.
Brake Lights Don't WorkThe brake lights and turn signals are on a separate circuit of their of their own and thus independent of the tail lights and side marker lights ["running"] lights.There could be several causes for this problem, and without being able to see and troubleshoot the brake light wiring circuit no one can tell you the specific cause.Some of the possible causes include:Brake light switch is not adjusted properly.The fuse for that circuit is "blown" out.A wiring harness connector anywhere in that circuit has become unplugged, or loose.The ground wire or wires for that circuit have become disconnected, or the connection of the ground wires to the vehicle's grounded body sheet metal has been blocked by corrosion.A wire in the circuit has been cut, broken, or pulled loose.The brake light switch has become defective.There are probably a few other causes I have forgotten about.