My 2005 acura tl just started to have this problem where the turn signal works and everything until you turn on your lights the light wont turn on. Same thing when i lock the car only one of the side light blink the other doesn't. Is this a electrical problem ? Can't be the bulb because the turn signal works.

 

Front turn signal bulbs have two filaments inside, one brighter used for turn signal and hazard lights, and one dimmer for running lights (lights that turn on when you turn on the headlights or lock/unlock the car).

Are you sure that it's not the bulb? Because it most likely is. Least expensive and simplest option is usually replacing the bulb, and if that doesn't help then you can whip out the diagram and start investigating.