Rear warning light on

Whenever I push the break, the Rear Warning light comes up in my 93 Mazda MX6, sometimes it is ON all the time when the engine is working, whether you push the break or not. At first I thought that it should be the break lights, but they were all fine. Does anyone knows what is the problem? Does anyone know how can I find an online manual for my car?
thanks a lot,

try some brake fluid... under the hood

thanks for the reply,
I tried that as well, it happened once before, and just adding break fluid fixed it, but this time the light is steadly up, do you have any idea what else it could mean?
thanks,

If you have changed the brakes recently, bleed them (correctly) again. Check the inside of the wheels/rims. They should be dusty, not grimy. Grimy would be a leak in one of the calipers.

a book you can get from a junk yard thats where i got mine or go to an auto parts store and buy a chiltons repair manual there like 15.00 i just bought one last month and there a big help, how about checking the break light switch thats a poss good luck

yeah ahh that same light was on in my car so i did all the things mentioned and then checked my ebrake theres a sensor thing on the drivers side i believe and it was stuck like the e brake was on so check that if ,not that i have no clue

My light is coming on because i have a burnt out light bulb.. cahnged the light bulb, now its off