Changing from a 3 prong to a four prong

Unplug the dryer then remove the terminal block cover and disconnect the 3-prong cord from the dryer. Note that the cord has red , black, and white wires but sometimes the red and black wires are both replaced by same color wire, usually gray and can switch places. There's also a ground strap wire also connected to the center terminal together with the white (neutral) wire.

Get yourself a 4-prong cord and note that it has red, black, white, and green/yellow wires but sometimes, like the 3-pronged one, the red and black wires are both replaced by same color wire, usually gray and can also switch places. All you have to do now is connect the 3 wires in the same manner they are connected as 3-prong cord to the terminal block. The ground strap wire now just need to be connected to the remaining 4th wire, the green/yellow wire instead of the center terminal together with the white (neutral) wire. Reinstall the terminal block cover and it's done.

It can be observed that converting a 3-prong cord to 4-prong cord is merely splitting the neutral line and the ground thereby increasing the number of prongs from 3 to 4 whereas, on the other hand, converting a 4-prong cord to 3-prong cord is merely joining the neutral line (white) and the ground (green/yellow) thereby reducing the number of prongs from 4 to 3.. The links below might enlighten you further on this matter.

Four-prong to Three-prong Electric Dryer Conversion
Three-prong to Four-prong Electric Dryer Conversion

It's either you convert the 3-prong outlet to 4-prong or the 4-prong cord to 3-prong. But the latter is easier and more feasible. Unplug the dryer then disconnect the 4-prong cord from the dryer. Note that it has red, black, white, and green/yellow wires but sometimes the red and black wires are both replaced by same color wire, usually gray. The red and black wires are lines L1 and L2 reversibly, meaning they can switch places, while the white and green/yellow wires are the neutral line and ground, respectively.

Get yourself a 3-prong cord and note that it has red , black, and white wires but sometimes, like the 4-pronged one, the red and black wires are both replaced by same color wire, usually gray and can also switch places. All you have to do now is connect these 3 wires in the same manner they are connected as 4-prong cord to the terminal block. The wire strapped to the dryer cabinet and connected to the green/yellow wire of the 4-prong cord wire is now left hanging. The last step is to connect this hanging strap wire to the same terminal on the terminal block (center) where the white wire (neutral) is connected and it's done.

It can be observed that converting a 4-prong cord to 3-prong cord is merely joining the neutral line (white) and the ground (green/yellow) thereby reducing the number of prongs from 4 to 3. On the other hand, converting a 3-prong cord to 4-prong cord is merely splitting the neutral line and the ground thereby increasing the number of prongs from 3 to 4. The link below might enlighten you further on this matter.

Electric Dryer Prong Conversion

There could be two situations for you. For the wall outlet, you may have a four prong plug or a three prong plug. For a three prong plug the outlet has three prongs and the terminals inside match up with these prongs. The two slanted prongs on the top are the hot terminals and the red and black wires get connected to these (order doesn't matter but keep the wires matched up with the terminals on the same sides). The white wire is connected to the "L" shaped prong, the third lower prong. The bare copper wire is just bent out of the way. At the dryer for the three prong there will be three terminals 2 hot and one neutral. Usually, your dryer cord will have the neutral as the middle wire, but pay attention if your cord wires are color coded (where white will be your neutral wire). At the dryer there is a terminal which is connected to the frame of the dryer by a piece of metal. This is your neutral, connect your neutral wire from your cord up to this. The other two wires get connected to the other two terminals (order doesn't matter but keep the wires matched up with the terminals on the same sides). For the four prong its very similar but there is a small change, that bare copper wire is now used. The terminals on the wall outlet will line up with the prongs. The two vertical terminals on the left and right are your red and black wires. The "L" shaped prong is your white wire. Now the fourth prong, the one shaped like a semi circle is the terminal you connect that bare copper wire up to that is your ground. At the dryer for the cord (If its a four prong cord your wires should definitely be color coded). The terminal that had a connection to the dryer frame now will no longer have one. The terminal thats connected to the frame you connect the green wire to. The terminal that was connected to the "green wire terminal' is now the neutral terminal and your white wire gets connected to it. The other two terminals are where your connect your last two wires.

Ok this is how you will wire the three prong to the dryer.

You have 2 wires that are gold/brass in color, those are the hot wires.
You have 1 wire that is crome/silver in color, that is the neutral

On back of fryer where you wire it you put the wires on like this right to left Gold/brass hot, silver/nuetral, then the other hot wire.

On back of dryer you will have screws from right to left this color gold/brass, silver/crome, then gold/brass again.

If you do have a 4 wire cord the extra wire is ground and you screw that to the machine body.

The three wire goes on the electrical block on the back of your dryer just like the cord is made. If you look at the cord, it's made flat (Most 3 wire cord are made flat, Some are not) The wire in the middle goes in the middle of the block. The two wires to the outside go to the outside of the block. It makes do difference which wire goes on which side as long as the outside wires go to the outside.
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DO NOT CHANGE THE POWER SUPPLY CORD.
you can't change the power supply cord.
the cord came with the dryer is 240v. the three prong is 120v. the dryer will burn up. if you change the power cord without changing the regulator , motor, and the heating element.
you need to get a electrician to run a 240v double breaker from the panel to the dryer.

four prong sould be installed as followed, black and red go to eitehr ends( amkes no difference which, white goes to middle and the green wire gets screwed directly to the dryer cabinet itself( usually an existing green screw just outside the connectin box. if there no power after that then check to be sure oyou indded have 220v going to the outlet

Click linl below

http://www.fixya.com/support/t1876622-three_prong_outlet_four_prong_cord_from
part number AP2615069

They wire in the same except the green wire will go to a ground screw which should be right in the same area with a green color to it. If no ground screw, hook the green together with the white (center) wire. Hope this helps!

use the ground on the machine.....There are 3 wires on the terminal block if you notice there is a grounding strap off the center post this will act as your ground to the machine back in your panel box the center post leads to ground anyway the other 2 are hot leads (240vac) use the 3 post you will be fine. you will be grounded let me know if you have any problems