g4ran

hi all i have a 1997 2.0 manual galaxy & the abs & handbrake lights are on all the time, i have cleaned all the sensors, but they are still on, i was told by an mot tester that you could check the sensors by unplugging them 1 at a time & putting a voltage meter on the plug then spinning the wheel & you should get a reading of 4.5 - 5volts i have tried this on all the sensors & never got a reading on any of them, so now i know that doesn't work, has anyone got any ideas the brakes seem to be working perfectly.