The ABS lights on my 1997 K1100LT continue to flash.  Battery is OK,is kept on a 'minder', & normally 'boots' the ABS without hesitation. The BMWExp. diagnostic printout shows ".17 Sensor front wheel", but their tech staff is unable/ unwilling to say whether the sensor is stuffed or there's a broken wire.  (No doubt they would prefer me to have them install a new sensor.  BUT, rather than buy a new sensor ("NZ$373.62 + GST" & fitting costs), & perhaps still get no cure, I'd like to know for sure where the failure is.  How can the sensor and the wiring be tested?  The electrical connection to the wiring loom appears to be hidden in almost impenetrable dusty depths under the tank & frame.  The sensor face appears to be scuffed as thought it's contacted the ring at some time.