So I have an 88 z31, the other night I was driving, and all of a sudden all of my lights flashed and my headlights went out. I tried my high beams and they worked for about 5 minutes then went out. I have checked all of the fuses and fusible links, as well as the headlight bulbs. I even went as far as to replace the headlight switch with a brand new one and still nothing. I have no idea what could be wrong and any help would be appreciated

 

Do you have a good ground ?
See if a test lite at the lamp plug stays on

 

Only times I had a flash followed by a black-out was when the bulb burned out. As to why all bulbs went out simultaneously, it sounds to me like a power overload.

Have you already replaced the bulbs?