My Gas whirlpool dryer model # LGR7646EQ2 wil not heat up.

SOURCE: Whirlpool duet electric wil not heat

Remove 1 wire from the element . Your 220 V comes from ...110 motor , 110 control board . Check which wire is not getting 110 V , trace it and see which it comes from . That will tell you which one is defective .

SOURCE: Whirlpool Dryer not heating

The motor has to be running for voltage to exit the motor going to the heater. With the back off the dryer and the motor running you should read 220 volts at the heater if all safetys and thermostats are good.
There is a thermal cut out relay on the heat canister. It must read continuity also.
Remember you must remove at least one wire from each component being tested to get a true open or closed reading. If a wire is left connected you get a false reading.
The heating element could be broken and part of the heater wire touching the canister. This would cause a continuity reading and still no heat.
Finally, yes,the centrifugal switch in the motor could be bad and not sending power to the heater on the red wire.

Testimonial: "I did determine it to be the cetrepetal switch..specifically the slide for the weights was heavily gummed up with dryer belt dust. It works now."