what could be wrong with my 1999 Chevy Tahoe if the tail lights keep going out?

[Geminisweetness]

A have changed the bulb and it worked for that day and the next day they was out again... I have checked all the fuses. So what can be the problem?
it's both of the lights...only the tail lights works and my third brake light.... the signal lights, back up lights and brake lights don't work on either side...

[Olger H]

could be the circuit board (that thing you stick the bulb in)

[al t]

Sometimes It Could Be A Cheap Bulb With An Aluminum Housing..........try Stepping Up (for Two Dollars More) For One With A Copper Housing............

[charles.paull]

if it has a trailer hook up in back itcould be shorting the tailights because of corrosion or a bare wire they usually hasve a T connection for trailer hook up

[A.L.V.]

i would check the ground or the switch
is it one side or both side
plus make sure you have the bulb all the way in the clip

auto zone sells electric grease for this and helps to the clip from corrosion