After removing the gauge cluster and reinstalling, the speedometer is resting at around 25 mph. I can reverse it by hand, but it won't register speed - doesn't change when driving.

I pulled the cable from behind the dash and watched as I was driving. It's turning and increases with speed, it just doesn't turn the gauge. Could it be a broken gauge? is there something electrical that also needs to be hooked up or is it just the cable? I am stumped and any help would be appreciated.

PS. the gauge worked fine before the disassembly, but we didn't put all the electrical components back together. That's why I am thinking it may be an electrical hookup that needs to be back together. maybe a fuse or another gauge that needs to be connected?

 

Are you sure you got it snapped all the way back in place? I don't think there's anything electrical to make the cable driven speedo work.

 

And, we're left to guess again.

This is the 87 to 96 forum. These trucks could have either a mechanical speedometer, or an electronic one. From your description, it seems you have a mechanical speedo, but you left out all info on your year and model. Checking your profile says you have a 66 F250 which belongs in another forum.

1961 - 1966 F-100 & Larger F-Series Trucks - Ford Truck Enthusiasts Forums

What will it be?

 

I realized i didn't include any pertinent information right after I posted it, but the power went out due to rain and I just now got back on. The truck I am talking about (at least the speedo) is a 89 F150, auto, 2wd, 5.0.

We took a 1966 body and mounted it to the frame and drivetrain of the 89. The electrical, gauges and mechanical is all still 89 - I haven't transitioned to the 66 dash yet (won't until the gauges all work).

Sorry for the confusion