Since both heater hoses are hot, I suspect that you might have a blend door issue, allowing the cold Michigan air into your truck and negating the heat coming from the heater core.

 

If that's the one you can see behind the glovebox with the white arm that comes out of the heater box with the cable attached to it, then it moves when I move the **** on the heater control. Is there another way to check it??

 

Read this http://www.haydenauto.com/fan%20clut...1/content.aspx

Dav e

 

I am having a very similar issue in a 97 I just bought. Apparently its been like this for atleast two years and had a heater core replaced in that time as well.

 

That's the recirc door, inside/outside air. The blend door is hidden behind plastic on center hump area, I believe.