No Speed Control.

1. Set sprayer to OFF and disconnect power to sprayer.
2. Remove the 4 screws to remove the enclosure cover.
3. Verify potentiometer is plugged to the circuit board.
4. Replace enclosure cover and four screws.

Resistance Testing

1. Set sprayer to OFF and disconnect power to sprayer.
2. Remove the 4 screws to remove the enclosure cover.
3. Measure the resistance from the black wire to red wire: 20k Ω
4. Measure the resistance from the black wire to white wire: 144k Ω
5. Replace potentiometer if measurements are not similar.
6. Replace enclosure cover and four screws.

Voltage Testing

1. Set sprayer to OFF and disconnect power to sprayer.
2. Remove the 4 screws to remove the enclosure cover.
3. Plug the system back in and turn ON power.
4. Carefully measure the voltage on the three wires. Voltage measurements:
        Black to Red: 5 Vdc
        Black to White (ccw): 0 Vdc
        Black to White (cw): 5 Vdc
5. If voltages are incorrect, replace potentiometer.
6. Replace enclosure cover and four screws.