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.
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
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.
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.
Check the park lamp relay. It is probably next to the fuse.