Bad day started with abs light
2000 ranger 4X2 2.5L 5spd manual.-----abs light on. Is off when truck is first started but comes on when brakes are first applied. New abs sensor in rear differential did not help. With directional signals on, speedometer malfunctions (needle jumps around), and it feels like engine is bucking slightly. Have no idea how the abs light and the turn signals/speedo could be related. Am lost. Any ideas? Thx. Jim a.