Check the wiring.

Unplug the unit and check that the wires at the terminal strip are OK (tight etc.).
Check for any signs of arcing on the line cord prongs.
Check for continuity of the line cord wires. Use the most sensitive meter scale. One meter lead goes onto a terminal strip connection, the other meter lead then goes on the corresponding prong. Now wiggle the prong to see if that line opens. If all OK also wiggle the wire/cord where it goes through the strain relief and at the plug end.

If all OK, flip the breaker off and check that the wire connections to the wall receptacle are OK.

Here are your parts
Parts for Whirlpool LEB6400LW0 Dryer - AppliancePartsPros.com

See the attachment for the tech sheet.

[COLOR="Blue"]I've seen numerous posts that say the timer is rarely an issue but these symptoms seem to point to it.[/COLOR]
Yes it does sound like it.
The ticking may just be the timer motor running.
In timed dry the timer should advance even with no heat.
So if it is ticking and not advancing it needs replacing.
Note that in auto modes the electronic control powers the timer motor so the circuit is more complex.

You can check the TIMER SWITCH 2 which are the contacts in the timer for the heater.
Unplug the unit and set the timer to mid scale timed dry heat mode.
Then measure from BK to R on the timer.
It should be 0 ohms.
When measuring across the contacts disconnect at least one side. This ensures that you do not read an alternate/parallel circuit path.
Also use the most sensitive meter scale
It is good practice to short your meter leads together before taking measurements. You will then see if there is any zero offset in the meter
re: zero may actually be an ohm or two.