I have a 90 honda accord with brake light problems. Here's how it goes:

When headlights are OFF:

-when I brake, the two front corner marker lights come on (as if somehow wired directly into
the brake lights)
-"brake lamp" dash light is lit

When the headlights are ON:

-brake lights stay on all the time, whether I'm braking or not
-dash lights dim when I actaully am pressing the brake pedal
-"brake lamp" dash light is lit

anybody have any suggestions? cuz I can't very well go around with my brake lights on at night all the time...

 

Check for a bad ground at therear lampclusters.

Then check for an un-wanted connection between brake & taillight circuits at the rear lamp clusters. This can also be caused by bulbs being installed wrong.

The combination brake/tail lamp bulbs actually have 2 filaments, & they have 2 little contact nubs at thier base. They're only supposed to go in the socket one way, but they can be forced in backwards to cause this problem. Or... a single-filament bulb was installed where it should be a 2-filament bulb.

Or... one time I saw the 2 little contact nubs at the base of a bulb had been mashed so the contacts inside the bulb socket would touch both nubs together.