Help me follow this please

[sept987]

71 gmc 350, I hooked up the starter and can't get the motor to crank. If i jump the starter it will, but nothing from the dash. I replaced the ignition switch and lock. I have a 3 wire starter with the purple wire closest to the block and yellow capped off after it splits to the coil. I have no power to my coil. Any ideas?

Also if your looking under the hood, the farthest driver side connector on the firewall has a brown, brown and white, and I think blue or black wire. It is cut off. Is that for the emmissions and tranny that I shouldn't worry about?

I have the wiring diagram but still can't seem to figure this out. Thanks for the help.