1992 F150 XLT 4x4 5.0

The speedometer seams to be stuck in calibration mode.
When I start the truck the speedometer clocks all the way to the right peg.
Then it goes back to Zero, and a error 3 shows on the odometer.

Seams to only happen after the truck has been sitting all night.
Drive to work, the speedometer does not work.
Go to lunch and all is well again.

Stranger than fiction.

 

Not that strange.

On the front of the cluster there are two plastic buttons, which are actually fairly long and go inside to and rest on top of two miniature circuit-mounted pushbuttons on the speedo/odo circuit board. One of the (I believe the left one? its been a while) probably has internal corrosion and is "dying". Eventually it will either permanently be open and not useful, or permanently shorted and not useful.

If you can solder, you can remove the four-pin pushbutton switch off the circuit board (it's through-hole, not surface mount like the rest of the parts on the board), or you can replace the entire board with a junkyard one, or even easier, just replace the entire cluster with one you purchase from a junkyard or ebay.

It's the speedo board, so unless you replace the switch itself, you're mileage display will be whatever you replace the board/cluster with, rather than what it displays now.

 

Thanks.
The problem has mysteriously cured its self as mysteriously as it appeared.
But...
I am sure it will be back, and I now have an idea of what is causing it.

Thanks again.