Are you saying you can't travel at all or you can't increase the speed limiter?
Using an SCR controller you can't really do much with the speed limiter unfortunately.
If it isn't letting you travel then somewhere in the travel circuit there is an issue. For an RC3000 the order is Brake switches, battery retainer switches (if installed), forward reverse switches, scr panel. If one of the switches is open, then no voltage gets passed to the next.
Also the pots wont do anything unless either the forward or reverse switch is closed.
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