2002 Genie S-65 Wont Drive In High Speed???

I have a 2002 Genie S-65 and it will only operate in slow speed (vehicle moving). This is also the first Genie lift I have ever worked on so this is a learning curve. I have the workshop/electrical manual for the genie and Im at a loss for whats causing this issue.

any help would be greatly appreciated.

Genie Serial Number #s60-8369

2002 Genie S-65 Wont Drive In High Speed???