Dryer runs, but no heat

We have had our dryer for about 5 years. I runs, tub rotates and blower blows, but there is no heat. I have taken the back off and found the heater box. I have a repair manual, but it does not address troubleshooting the circuits. I understand there are a couple of fuses in the heater circuit, but don’t know where they are. I have a multimeter. can you give me some direction on how to proceed and what elements to check?

Here are your parts
Replacement parts for WHIRLPOOL KEYS850LE0 | AppliancePartsPros.com

Here is the wiring diagram
http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%203406681.pdf

First try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker and the heating coil requires the full 240 volts.
If this does nothing.
Measure the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the unit’s terminal strip to ensure they are properly connected and none of them have burned off
If OK
Plug the unit in and check the voltage at the terminal strip. This is just in case you have a bad line cord. Be careful 240 volts is lethal.
If OK
Unplug the unit and check the heating coil and thermostats etc. for continuity.
Heating coil, each side should be 20 ohms approximately.
Thermostats and thermal fuse all should be 0 ohms.

Be sure to disconnect one side of and device you are measuring this prevents reading an alternate/parallel circuit path. Also use your most sensitive ohms scale.
There is a good Sticky at the beginning of this forum on meter usage.