[wtelwe]

My dryer heats only on medium setting. Runs on low and high but will not heat

[denman]

Here are your parts
Model KEYS750JQ1

Here is the wiring diagram
Model KEYS750JQ1

Have you tried both timed dry and auto modes?

When you change temp settings you are changing the resistance in the Temp Selector switch. This is in series with the Thermostat Heater which is inside the cycling thermostat. It adds heat to the thermostat so that it switches off more frequently when set to the low heat setting 10 ohms therefore less heat from the main heater. At the high heat setting 10 kilohms, it heats less so the the thermostat gets most of it's heat from the main heater therefore is on more and therefore higher heat.

Could be the Temp Selector is shot.
Best way to trouble shoot is remove the wires from it and check it with a meter for resistance at the different settings.

This is weird one!!!