This 1995 Pontiac Sunfire came in with several electrical complaints among which were the headlights flicker or flash, the radio turns off any time any lights are turned on or off, multiple dash warning lights flash on and off and the engine is sometimes hard to start. Sounds like a major ground or power fault to me and sure enough it was a faulty body ground. Some one had changed the negative battery cable but failed to install the body ground. Of course if you look at the bottom of the battery tray where the ground is supposed to attach the whole corner is rusted off.
I found a safe convenient location and attached the ground lead to the body. By safe, I mean that there is nothing behind the panel to be damaged by the screw. A simple fix to repair what seemed to be a very complicated problem.