When I turned the key to start I heard a pop and all power died.Had 3.5 volts at the battery..Installed a new battery and the same thing happened,this is why I am here..Do you think it is the starter?

 

A pop? That doesn't sound right. Was the battery that you replaced bulging at the sides? Have the battery cables ever been replaced?
Last question, i almost feel weird for asking. Are you sure you put the red to (+), and the black to (-)?

 

no sin in asking the simple question,The old battery was five years old and i just said" what the heck" still has original battery cables

 

Happens only when you turn the key to "start"?

Sounds like you have a dead short to ground, check the positive cable to the relay and from the relay down to the starter.

Melted to the exhaust or pinched some place?

The starter may have a dead short in it, check it if the cables are clear.

 

sounds like a good plan,thank you

 

Sounds like you have a few things to do. But if you don't have a Haynes or Chilton, that would be your first step.