When troubleshooting electrical problems with appliance, like no-heat complaints in dryers, you absotootly gotta have the wiring diagram / tech sheet that comes packaged with the appliance. The manufacturers cleverly hide these inside the appliance to keep owners from finding them and losing them. I love when I go out on a job and need the tech sheet but it's been removed from the appliance. The customer then informs that they took it and filed it so it wouldn't "get lost" but they can't find it. Folks, that's a show-stopper. You cannot troubleshoot electrical problems, except for the most simple and obvious ones, without the tech sheet. Just ain't gonna happen.
Strip charts are nice because they focus only on the circuit and components involved with the specific complaint; in this case, no heat. Let's take a look at the heater strip chart on this beast:
I've highlighted the key components in the hearing circuit that should be checked. You can start with resistance checks if you like. Note the thermistor resistances are given.
But being as how I am an experienced appliance warrior, I like to do live tests with the voltage on the circuit.
This is especially easy in this case. Just disconnect the two common wires from both heater relays (violet and red wires), secure the wires so they don't touch anything and then run the dryer on a heat cycle. In a properly functioning hearing circuit, you'll have 120vas at both the NO (black) and the violet and red wires that were disconnected from the heater relay. Whichever side is missing the 120vac is the problem side.
Can also disconnect the common wire from the heating element, secure it, and run the dryer. See with side of the heating element circuit isn't giving you 120vac: either the control side or the motor side. Whichever is missing the 120vac is the side with the problem.