So I have tired lots of things and get this relay to work right.
I tired with a tip120/tip42/s9013 and the pin can't control the relay.
I was thinking that the Arduino can't supply enough power to turn on the relay. So that it why I tired the tip42, but when I set it to LOW it doesn't go completely low, I can still measure 3.6v. What am I missing? Or can I not use the tip42. I figured if I switched power to the relay coil then I wouldn't need to draw anything from the Arduino pin.
????
Thanks again.