Ok, so today I bought a new blower motor put it in and I had HEAT! for about 3 hrs. then out it went again. Hooked the old blower up in the house and it works, so I apparently didn't need the new one.
What now?I have a completed circuit to all wires. Think I have a short somewhere? Bad Ground? They checked the resistor at the dealer said it was fine,but it did have a visible crack could that be bad?

 

Check for recalls and TSBs. There was something about the plug on the wire harness to the blower motor getting hot and unplugging itself! Had mine done a couple of years ago.