Parts of a model won't texture

I have imported some models i made in blender into unity, rather than making a skin for it, I instead just textured each component in unity, but there is a problem. I imported a truck i made, I put blue flames as a texture on the hood, but on other parts of the truck I try to put a texture on, for the tires I had put a tire texture, which was brown and black. But instead, it didn’t texture the tire, it made the tire a solid color brown, how can I fix this? I’ve tried everything in unity and blender to figure it out, but no solutions.

Try this:

  1. Select all vertices in your tires.
  2. Press U
  3. hit Reset (or reset UV, can remember what its called)
  4. save your model under a new name
  5. delete the old in unity
  6. restart unity
  7. import the new model