Abs Light 06 1.4 Fiesta,what Else Could It Be

Hi new to this so be gentle with me

ABS light on dash,everything else on dash working as it should,no other fault with car.

Garage diagnosis c1236 no signal nsr wheel,i changed rear sensors,garage turn light off but came on again,

Took car to main ford dealer next day they checked it out and diagnose faulty abs module(they wanted £805 to fit new one)

Found an ecu repairer online which was recomended and sent it off them,they found no fault with ecu but i had them rebuild it incase it was an intermittant fault and they have given me a gurantee,

Purchase software to switch abs light off myself,

Refit ecu to car,bleed brakes,road test,light came back on

Check for continuity from ecu block connector to rear block connector on axle all ok and checked the same for the front wheels all ok,road test and light came on,

Checked all sensors and they all gave the same resistance

Remove and fit nsr wheel bearing and new magnetic reluctor ring to brake drum switch light off,take for test drive and you guessed it the abs light came back on,

Im realy running out of things to change ,there must be something im missing,after ive spent all this time on it i really want to beat this fault

Any idears anyone,