my system aint worked for ages and mots up next month so i decided to have a grin and see whats up with it tested everthing loom, resistance in the sensors at the ecu ect found 3 sensors not sending a volt to the ecu . so i strip a sensor out and clean up the seating area start getting a reading but not a strong one any ideas to y this is happening whats the best way to service the abs or shall just rip the lot out ?