I'm having an issue currently with using an N Channel MOSFET. I would like to control a 12 volt LED using an Arduino Uno. The Uno puts out 5 volts. The issue I am having is that the 12 volt LED stays on but dims if there is no signal being sent from the Arduino. If there is no signal the 12 volt LED should turn off complete. The Uno is programmed with a simple blink program to test the LED. I connected the Gate to a pin on the Uno with a resister in between. The drain is connected to the 12 volt LED from the 12 volts being supplied from the bread board. Source is connected to a ground. There is another pin connected to the blue LED with the same code. So I knew when the 12 volt LED was supposed to blink.
I am using FQP30N06L MOSFET from spark fun. 12v LED. 12 volt wall adapter.