2000 reg my brake warning light is on all the time, indicating the pads are low, but I don't have the wires connected, when I bought the car the wires that pad wire attaches to had been joined together, the light came on the odd time but if car was switched off & restarted the light went out & stayed off, but now it is coming on all the time, fluid is fine, I have separated the wires to try & solve this but its made no difference,

 

You need to short the wires together to turn off the lamp. The connection between them before was probably subpar and intermittent, causing the lamp to come on occasionally. Splice them solidly and the light will be out for good.