1999 chevy tahoe 4 door 4x4

the brake lights do not work at all left, right, and third
third brake light does not come on at all. (i can not get it off to check it. it is sealed to truck)
the right rear turn signal is dim but works
took apart and cleaned connection on both tail lights
the turn signals both blink very fast
cleaned front sockets for lights
hazards work fine except for the dim light
all fuses are good
all bulbs are good
i have replaced the brake petal switch
any help would be great.
Is there a trick to taking off the third brake light

 

If the fuses, bulbs and connectors have all been checked.. then possibly it has something to do with the wiring. Have you tested to make sure the proper amount of power is being sent to the lights?

 

Turn signals blinking fast indicate a bad bulb or a bad connection to the bulb. You cleaned the sockets but they still might not be making a good connection. Maybe they need to be replaced. A bulb being dim also indicates a poor connection. Also check to make sure you are getting a good ground connection to the bulbs.