https://www.youtube.com/watch?v=BGF01ItsISo
https://www.youtube.com/watch?v=AK9LQNc_BfY
Newer homes are now being equipped with 4-prong dryer cord plugs. This is the new standard and is required under Article 550.16(A)(2) of the National Electrical Code (NEC) 2008. Connections of electrical clothes dryers shall be made with a 4-conductor cord and 3-pole, 4-wire, grounding-type plugs or by Type AC cable.
Good Luck...
March 2016