won't start....

^^Do what kendog posted^^ Ground that terminal, or take the NSS wire's terminal to the NSS and clip that to ground.
Make sure the selector is in Park.
Turn the key and if the starter cranks then you know the relay wasn't getting grounded.

Abodysrule said

But even when it's showing power, the ignition wire to the starter isn't getting power when I turn the key. I tried in park and in neutral. My battery is good, I bench tested the starter, it's good. My headlights, flashers, etc. all work. Is this perhaps a bad ground to the engine? Any ideas?

Click to expand...

Abodysrule said

I also note that my horn isn't working. I hear the relay click, but no horn.

Click to expand...

Horn is power is joined to the main circuit at the alternator.
IF the battery is charged and in good condition, then the connection or wiring has too much resistance for the higher current needed to run the horns.