Dryer will heat up in automatic dry mode but will not heat up when on Timed dry mode. What is causing this?
Here are your parts
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=WED5100VQ1
See the attachment for the tech sheet.
The most likely culprit is the timer.
This can be checked by unplugging the unit.
Put it to the timed dry and check across A to B.
It should be 0 ohms.
Be sure to disconnect the wires either from A or B. This prevents you from reading an alternate/parallel circuit path.