E-Z-Go Customer Service Issues

I own an EZ Go cart with the data tag number E[redacted]. The issue I'm facing is that the solenoid on the motor controller activates as soon as I turn the key and put it in forward or reverse, remaining on regardless of the throttle pedal position (which is properly adjusted). The yellow and blue wires were damaged against the battery, causing the cart to stop working. After fixing those wires, the cart now only reaches a speed of 4 to 5 mph, accelerating quickly but then slowing down. The batteries are new and show a charge of 38.20 on the pack. When checking, the A1 terminal reads 38.2 volts at rest, dropping to 19 at full throttle with the rear wheels off the ground. I'm unsure if the solenoid should only activate when the throttle pedal is pressed. Any ideas on why it's moving so slowly? Additionally, there are no fault codes in diagnostic mode, and it beeps four times to indicate performance mode.