My speedometer on my 1999 picup stays at zero until around 35 to 40 and then jumps up. Works smooth and accurate including cruise control until I drop below 35. It then goes back to zero.

I braked hard about 400 miles earlier when a car and a truck mixed it up in front of me. I then noticed the abs light on. The speedometer worked fine on the rest of the long trip.
Are these related? Is there a reset?

Thanks

 

The sensor on the differential is either covered with metal (inside the diff) or failing. A new sensor is under $15 at the Ford dealer. There is only one bolt and one wire connection to change it.

Mark

 

Thank you Mark.

I certainly feel good about that answer. I will report back as soon as I get it switched out.

 

The part was easy to replace and everything now works perfectly. I was really worried about a major problem but am now greatly relieved.

Thanks again Mark!