Speedometer not zeroing

[f100cleveland]

Went to town to wash the truck today and it seemed like I wasn't going as fast as the speedometer said. When I stopped it only went down to 16 mph. Driving through town I had to keep it around 45 mph to stay with traffic (30mph). After I cleaned her up and headed back home it read 11mph stopped and seemed to be about that much off cruising home. I checked the odometer against mile markers and it was on. Any ideas whats wrong?????? Its zero degrees outside but that shouldn't matter.

 

[f100cleveland]

Well today it was workng fine. It's warmer today but I'm sure it will get below zero again to give it a test.

 

[pete37922]

that happened 2 me also...as it got warmer the speedo seemed 2 be workin again...weird !!!