Electric cart acting up

[cstober]

Hello All!
I have been running my 1986 G2 custom build project now for 6-7 months. It has one of Carts Unlimited's Cu54 universal kits in it with an altrax controller. Over the weekend I have lost forwards twice after making a trip up our gravel trail from our boat dock. The cart has made this trip several times before without incident.

The cart made it back to my house both times in forwards but once I hit reverse, it wouldn't move forward. When trying to get it to go forwards, you can feel the cart shuddering like its trying to go but can't. The controller was blinking once green and then 6 red blinks. That was supposed to be a stuck solenoid so I purchased a new 400 amp solenoid. Replaced it and still no forwards. Checked all the cable connections between the sw202 and the motor and all seemed to be tight. Wiggled the wires from F/R switch to SW202 and boom, I had it working again. Until the next time I took it down the gravel trail...

My questions are:
If the connections from F/R switch are getting jolted loose on gravel trail, shouldn't the cart quit moving forwards right then instead of getting me the rest of the way to the house?

Is it normal for the 2 gauge cables to get really hot between the SW202 and the motor? The S2 cable was pretty hot the second time this happened and I went to wiggle the wires from F/R switch.

I don't think this is an issue with my custom built motor as the cart has never lost reverse both times this has happened. I want to thank you all in advance for knowledge you can share as this is my first foray into electric carts!