lolcol11:
I made a HUGE mistake, right?
Yeah
But that doesn't really relate to your problem of only pin 8 activating the relay and not eg pin 10. so to solve that problem, disconnect the motor side of the relay* and your sensor from the arduino, and just see if the relay activates by itself running blink, but on various pins.
- I'm kinda hoping you did that already before you fry yourself....