How do you test diode using multimeter?

A Diode will pass the electrical current into one direction, and will produce high resistance in the opposite direction. To check a diode, use an Ohm-Meter or a "multi meter", and set to measure resistance "Ohm", in the 1k Scale. You will have two leads in the ohm meter + and - (Red and Black) If you measure the resistance in one direction ( red lead touching one of the diode leads , and the black is touching the other lead ) , and you found a low resistance in one direction, and a very high resistance in the other direction ( by reversing the red/black leads) , this diode should be ok. If you find low resistance in both directions, this diode is shorted, and is damaged If you find high resistance in both directions, this diode is open circuit, and is damaged