ok..... if I have an '85 trans AM... if I hit the brakes only 1 light turns on on the tail lights, instead of 2. (on each side) and when I turn my blinker on it doesnt blink it just stays on.. and it also trys to use this same light so it doesnt work. what the hell is wrong?!

 

yep, this is the way taillights will behave when there is a bad ground or the bulb fails in a certain way.

(are multiple ways for dual filament bulbs to fail. even if one part of bulb has burnt out, bulb may still light under certain circumstances.)