I have a 2004 chev Express box van and my tail lights wont work every blinker works just not the lights both sides replaced bulbs still nothing

SOURCE: no dash lights and no tail lights

Check for faulty wires at the fuse block, had one fall off from the block itself from the rear, or it could be a wire break somewhere along the way.

Stop Lights and Blinkers are independant fuse.

Tail lights are on there own fuse and could be a wire break in the rear or removing the bulb and using a metre check for signal at bulb socket where trouble is, Check for disolored connections, Green in color or simular, could be a bad connection which in turn is not letting the curent to other side, Causing a short and loss of power to all remaining lights in curcuit.

SOURCE: 2001 dodge neon tail lights inop

looking at your schematics and , you say tail lights don't work , you didn't mention if front parking lights and license plate lights are working , they all come from the same source , a black /yellow wire , a good clue if front work and rear don't , please advise .if fronts work then you have a open circuit somewhere between junction S118 (near breakout for left headlamp) and rear sockets.

SOURCE: 1997 GMC Sierra p/u. Brake light & blinker out. Lamp & fuse ok.

you probably got the wrong bulb
those are usualy a different number higher wattage, they look exactly like an 1127 but are a 2027 or even a 3027 check the bulb base it has the number printed on it

SOURCE: brake lights won't work. tail lights do. I

need to know if your third brake light up high is working or not.if it isn't,you need to check the brake light switch on the brake pedal with a test light,one side hot all the time,the other side should turn hot when brake pedal is pushed.

SOURCE: 2006 Cobalt rear driver side blinker doesn't blink

More than likely its the bulb, the bulb has two filements, one for brake and one for turn signal, If you take it out and hold it up to a light, i bet youll find with a close look one filiment is broken!