the drive potentiometer should read 4,5 volt in neutral. correspinds with 2650 ohm. If not the relais click but slow pulsing.
You can adjust the potentiometer bij listening to the microswitches.
it works like this: the potentiometer is used by the drive controller to determine if it should drive and in which direction. The accelerator microswitches are there for safety: it is a check for the controller if the potentometer is correctly adjusted and not broken.
potentiometer is pin 6-7-8. switches are in parallel on pin 9-10

The clicking of the switches should be at the same time that the relay clicks. Symetrical forward and backward. If not, you should adjust the potentiometer.

After readjusting you have to recycle the key switch to clear the error.