I have a 2012 F150 Platinum

My speedometer is set at 15mph even when I am not moving. Then it goes up from there when I start driving

This is a little confusing.

Anybody know what I need to do to reset the speedometer needle to 0mph?

 

Assuming it's not faulty, i've seen people carefully pull the needle off and reset it, takes a bit of care, trial and error.

 

I don't know If this will reset it but you can hold down the ok button on the multifunction wheel of you have that and it will go through a cluster test when you start the car if I recall. If it doesn't do the full sweep then I would say your cluster is defective.

They are pretty cheap on eBay, you just need to get the miles programmed.