The speedometer on my 2006 F350, 6.0L diesel went wacky for a few days--would read 50 MPH when parked with engine off or maybe 100 when driving through town at about 35MPH. Thought it was a warranty repair issue and was going to schedule a visit to the local Ford dealership.
Then, mysteriously, it began to work again. I haven't replaced any fuses and have simply been driving it as I customarily do.
Obviously, not a big deal but I'm interested in any explanation.
Thanks for any ideas...snaffle bit.