On the pedestal above the brake pedal is the switch, First thing to try is to lift the brake pedal up and see if the light goes out. If it does than adjust the switch inward a little. If it doesn't than chances are the switch is NFG. Other things to check would be the pedal return spring. The switch is a closed circuit keeping the brake light on all the time. When the brake pedal is up the adjustment should be such that it opens the curcuit and the lights go off.
i had this problem and it was caused by these little rubber bushing that were in a plate just above the brake pedal. the pedal comes back and the plate where the bushings are push the switch and lights go off. these bushing get old and crumble apart, so i replaced them with a bolt, washer and nut. havent had ne probs since then. also the OEM bushing are available at nissan i believe. but i would say my route is alot sturdier.
its called the "stop light switch"...
was the first thing to go out on my ZX..
had to disconnect the battery every time i parked until i fgrd it out..
its a rubber dealy that fits up on the top of the pedal..
though most likely yours isnt there...
look in a manual or something..
should only take you a minute to change.. and it costs about 4 bucks...
but dont take your car to a shop like i did..
do it yourself ... and save 75 dollars in labor.
i noticed this yellowed translucent plastic stuff on my floorboard under the pedal.. which i'm assuming was the "switch"
not sure why its called a switch.. beings its only a rubber thing.. that i assume pushes a switch?
anyways... thats probably your problem.
Mine stayed on and I got down there and noticed that there was a hole right over the spot that depresses the switch.I had just installed a new master cylinder and it had some little plastic protectors over the nipples on the MC. These little plastic protectors fit exactly in the hole. I put one in and my brake lights go out every time I take my foot off.....easy (and cheap )fix
I cut a peice af aluminum one inch square .032 thick I recall, and glued it on with RTV. epoxy would not take the repetitive shock. I also found out that the same thing was the only thing wrong with my cruise control ( one on each the brake and clutch pedal)