Hey Guys, I have the exact same issue as the originator of this post.....same model Whirlpool dryer. I hope it's okay that I resurrected this thread.
I've checked the Door Switch, Thermal Fuse, Timer, and Start Switch - all seem to be okay. I've also checked the continuity of the White & Blue wires as fairbank56 suggested - they tested good. 120/240 volts are present at the power entry point.
I checked power at the timer, over to the Start Switch and then down to the Blue wire at the Motor - I have 120 volts at the motor (blue wire) when I 'start' the dryer, but the motor doesn't turn. I don't hear the motor making any noise (humming) at all when the 120 volts is present.
At this point, I'm thinking the motor is shot, but I wanted to see if you folks could think of anything else that might prevent the motor from starting......I'd hate to order a new motor only to find that something else was actually causing the issue. And I'm not so sure how common it is for a motor to completely die without 'acting up' before doing so. I can turn the motor by hand with some slight resistance.
I don't know if it matters, but the dryer was working fine this morning. It dried one load and it was in the 'wrinkle guard' mode. It never started again once the second load was put in it.