I just got my truck about two weeks ago....Its a 99' F350 4x4 powerstroke....We went on vacation this weekend and the abs light came on....I am guessing that a speed sensor or something has faulted, but shortly after the speedo would act up. Every now and then its just drops off and returns to the speed I was traveling at. Just wondering if anyone else has had this problem or wether or not my guess was correct(speed sensor) and if whats affecting the abs might also be affecting the speedo......I can only imagine what the stealership wants to diagnose this....Thanks for your time.....

 

Just get a speed sensor on the rear diff and put it in yourself and save yourself a bundle.....

 

Yuuup. VSS is thirty bucks or 190 bucks installed. It takes two minutes. Boy, service doesn't mean what it used to. Might also want to pull your rear diff cover before you change the VSS to make sure there is no damage to the tone ring(which causes the vss to work) and that there is no transient metal scraps in the oil, or it will blow the new one, too.

 

thanks alot.........one other quick question that might also be related, the overdrive off light on the shift lever blinks when the speedo is not functioning, could this also be linked to the same deal.. Of course the manual says that its due to malfunction and to contact the dealer asap to delay any further damage.........

 

Yup change it now...

 

thanks again to all...