i replaced the ignition relay switch, still does nothing, battery is good, any guess as to what the cause is??

Starter solenoid? The starter itself? What happens when you try to start, does it turn over once?

"Still does nothing."
I assume this means it won't crank?
Check the battery connections, including the engine ground and starter post. Check to see if it cranks when the relay is jumped (vehicle in PARK or NEUTRAL). Run a jumper straight to the starter post if all else fails - if it doesn't crank then, replace the starter.
Again, when you try to crank the engine outside of the vehicle - make absolutely sure it is in Park or Neutral.