ABS and Brake light on Speedo not workin

[James M]

I've got a 98 Dodge Ram 2500, 12 valve, 47RE. The ABS/brake light combo has been coming on and the truck was initially pulling to the right when I hit the brakes. Bled the brakes and replaced with fresh fluid, which solved both problems, however the lights have come back on again, now with the speedometer malfunctioning. I replaced speed sensors in both the rear diff and the transmission with no change.

 

[GAmes]

Did you check the wiring to the rear sensor? I don't think the one in the transmission is in the loop.

 

[DavidC]

Yeah, rear sensor. Check the wiring real close. I have read of wire failure where the harness will flex from the frame to the axle. I have also read very rare tone ring failures in the differential.

 

[Joe Mc]

That's what it was with mine, wiring chafed, can't remember if from frame to diff sensor or from trailer connection to harness. Was years back but once found was easy fix.

 

[James M]

You guys hit the nail on the head. Culprit was one of the wires going to the speed sensor in the diff. Barely even exposed and hard to see where it had frayed with the naked eye. The damage was located right near where it left the frame. I probably wouldn't have found it if I hadn't been looking. Thanks for the advice.

 

[DavidC]

Another successful ending, glad you found it.