i'm having some issues securing the taillights on my `77 corvette. i've checked the connection, and its fine, checked the bulbs and they're fine. i bought a news pigtails, and wired them in -- they are fine, but when i go to put the cover back on the bulb and secure it they dont work. when the lights are on and you wiggle the bulb it lights up but other than that there is no illumination. any suggestions??