So I did some more trouble shooting.
I disconnected those capacitors. No effect, still hesitates and sparks.
I took it apart again and wiped off the grease to get a better look. I found where it was arcing, making that spark and thus causing the hesitation and blowing fuses.
I also noticed that the copper finger that was running furthest out looked like it might not be making contact at 100%. I bent it in a touch. It actually swiveled in. The finger that was arcing also looked like it wasn't sticking out as far as the others, so I bent that out a bit.
I reapplied some of the grease I had removed, and put it back together. Still does it.
I then started disconnecting the leads and when I disconnected 31b, it stopped that sparking/hesitation crap. I was wondering why there were two grounds???? Anyway, it works, low, high and park.
Does this make sense? The way Justin explained it, one of the features should not work? Maybe I should be happy it works and stop overthinking it.
When the switch is in the Low or High position, the 31b terminal on the switch is (or rather supposed to be) physically disconnected internally. Removing the wire from the 31b terminal on the motor should have had no effect when running. That leads me to believe that either the wiring is mixed up or the switch is bad. Doubly so when you say the motor can still park with that wire disconnected.
On the motor in the picture above, the terminals from left to right are 53a, 31b, 53, and 53b. All four should go to the corresponding terminal on the switch. The single terminal below those four is 31. That should be a permanent connection to ground, that is one of the two ground wires in your harness with ring terminals.
On the switch, if you pull the connections off, you should see the terminal numbers printed next to the six posts. 53a, 31b, 53, and 53b should go to the corresponding terminals on the motor. 30 is for power (red wire). 31 is a permanent connection to ground, that is one of the two ground wires in your harness with ring terminals.
My best guess is that they mixed up the two brown wires on the motor. If the motor's 31b terminal were connected to a permanent ground instead of correctly through the switch, that would cause a short whenever the switch is in the Low speed position and every time the motor passes the park position. It would also cause hesitation as most of the current is dumped through the short instead of powering the motor. I recommend you double check the wires are going to the correct places.