This is a replacement KitchenAid Mixer Speed Control Plate, the speed control plate controls both the speed of the mixer and it’s on/off function. The speed control plate is found in many of KitchenAid’s 4.5 and 5 quart mixers, including models that start with K45, K5SS and KSM.
The speed control plate is approximately 3” by 2 1/8” (not including terminals on side). The speed control is located at the rear of the mixer, and is visible once the mixer end cover is removed. The speed control has a screw located at the bottom that holds it in place, and also two speed adjustment spring loaded screws on the top.
The speed control plate, WPW10119326 will replace the W10119326, 4176137, 4162402, and 240904-2.
A common problem with the speed control plate is when the speed screws come loose; this will cause the mixer to only run on high speed, even when the mixer is on a slow setting. Often you can open up the mixer and tighten the top screws (left to speed up the mixer, and right to slow it down) and the mixer will return to normal speeds, if adjusting the screw does not work you may need to replace the speed control plate and the speed control phase board.