1999 Ford F250 ABS light on, Speedo Not Moving, Overdrive Light Flashes.

[Lizardman]

For the last 4 days in the morning my 1999 F250 7.3 liter 4x4 diesel has started with a solid ABS light. If you try to drive, the speedo doesn't work and the overdrive light starts flashing. In reading extensively on the forums, I started with the rear differential VSS sensor. I pulled it out and cleaned it put it back in. Still the problem persists only in the morning. In the afternoon the ABS light has yet to come on. I was curious if this could possibly be the output sensor on top/back of the tranny. I have yet to come across an issue where its occurring in the morning. Any thoughts? I might just go buy the VSS sensor for the rear and check that.

[wbones9]

go buy the VSS sensor. Mine did the same thing.

[travisj1987]

^ exactly what mine did, my sensor wasnt out but the wire going from the main wire loom to the sensor has a small crack. when the tape and loom wasnt cracked. Took alot of ohm testing to find it.

[Lowdown89]

Hopefully it's not your speed sensor ring, mine was doing that, I replaced the Vss and it still didn't fix it pulled the diff cover and somehow the speed sensor ring was gent! Also when you pull the Vss out they have a bad habit of coming apart so lime the other said just replace it it's only like 20 bucks at ford