Speedometer not working

[Mason_lloyd]

Okay, I took my truck to a shop to get it bulletproofed and other mods and when I went to pick it up, the speedometer wasn't working. They tried to work on it but weren't able to fix in the time because I had to be back for work. I took it back for them to try to fix it but so far haven't had any luck. I'm just trying to help them diagnose the problem. I don't know what they have tried to fix it.

Abs light is on and it wasn't on when I took it there (I don't know of that plays into why speedo isn't working).

From what I've googled, the VSS? Can cause this. That is the sensor that plugs into the rear differential.

Any help would be much appreciated. Thanks guys!

 

[Trqmnstr]

Yes the VSS is the one on the rear diff that has something to do with the air bag system.
The ABS light could also be the anti lock brake sensors on the front calipers. Pulling the VSS and cleaning it as well as the brake sensors might get the light to turn off. Worth a try before buying a new $70 VSS sensor (thats what napa charged me anyways). My light is still on randomly so my prob isnt the VSS.

As far as the speedo i bet a harness is loose or a wire got pinched when the cab went back down.

 

[ghohouston]

Or your problem could be that napa sensor^

 

[Trqmnstr]

Ive never had probs with any napa parts.

 

[ghohouston]

Fords dont really like aftermarket sensors. I cant promise you its the issue, but its well documented, they almost never work on ford diesels.

 

[Trqmnstr]

Guess ill clean the old one and put it back in when i get a chance and see if that works.