I got it working!
Thanks so much for the reply. The problem was intermittent, as I was actually able to get it working a couple times yesterday, randomly. I pulled all the wire harness connectors apart and cleaned them with compressed air. Along with blowing as much dust as I could get out of the rear compartment. I still have no idea which connector it was, but that did the trick. I see now that I have two forward contactors and two reverse, interesting.

Now that it's working properly, I can get a helper in the driver's seat and poke around a bit in the back compartment to see which/how circuits are used.

Thanks for the heads up on the switch at the pedal.