wiring issue????help

[mrenj23]

I turn the key and nothing, no click, nothing. CD player turns on, battery has plenty of power. Has done this a couple of times now and the first time I changed the starter. Worked a couple times then quit. It will works erratically but very inconsistent. I hooked the purple wire to a 12v source and the starter bumped over. I tried cranking it with my head lights on now they don't work either. I'm so frustrated please help. Is it a ground issue or what???