2006 F-53. Doing brake overhaul found rear rotors did NOT have ABS rings in them. Both hubs have ABS sensors, this is a 4 channel system. I had no ABS light on. Stupid me went and replaced the rot...
All sensors tested good today. Found air gap on these is pretty large but spun front tire around while measuring and it did generate some voltage so good sign there. Tore down the rear end again. New rotors coming tomorrow.