Dryer won't run (after replacing almost every part)

Hi I have a Kenmore dryer 400S. A couple of months ago, it quit working midcycle. I vacuumed it out, checked the door switch, replaced the motor, replaced the timer switch, replaced the heating element, and replaced all four fuses. It does the same thing: it activates the heating element but the motor doesn't run. I've rechecked the motor install four times so I know it is in there correctly, and I replaced the fuses twice just to make sure I didn't get a faulty one. The only thing left is the wiring... but I'm hoping there is a simpler answer that I somehow missed. Can someone give me some advice on what to do at this point?

I should mention that I installed the dryer motor, checked it, then installed the thermal fuse. At this point the dryer ran again (so I knew the motor, fuses, timer switch, and power worked). Then it shut off after thirty minutes- same as the first time when I first began to replace items. So here I replaced all four fuses. It ran again for thirty minutes. Then it quit. So I changed the heating element and four fuses (again). It didn't run again. Now I turn the timer switch to timed heat and the element activates but no motor- like when the problem started. If it didn't keep working, I'd worry about my fuse box (which I checked) or the power cord or any number of parts. However, it seems to reset with new fuses but then quits again.