Here are your parts
Replacement parts for Whirlpool LEC6848AN1 ELECTRIC DRYER | AppliancePartsPros.com

See the attachment for the wiring diagram.

. I have replaced the thermal fuse, drive motor, cycling thermostat, thermal cut-off kit and door switch.
The cycling thermostat and thermal cut-off have no effect on the motor starting.

Here is the start circuit for timed dry.
NEUTRAL , DOOR SWITCH D1/D2 , TIMER SWITCH 4 T/W , motor's centrifugal switch , START and MAIN motor windings , THERMAL FUSE , PUSH TO START RELAY R2/R1 , timer contacts BU/BK , L1 120 volts.

Since you have replaced a lot of the parts all that is left is the timer contacts and the start relay or you have a bad connection in the circuit.

If you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.
4. When you start always short the meter leads together. This will tell you that the meter is working and if there is any 0 offset.

There is a good STICKY at the start of this forum about it's use.