Had a similar issue with the 780 in the picture. Abs light kept coming on and no one could find the answer. Turned out to be two things, er three. The holder for rear drive rusted out, next left front steer wheel bearing failed and finally the in line fuse holder for elm melted. The cheapest was the ecm fuse at $300, wheel bearing with tow $2000, holder $1500. Hopes this helps.
I just read my post from Feb 22. Autocorrect The holder, should be The ABS sensor holder on one of the rear drive axle rotted out. elm should be ECM, it was a inline fuse.
