bucking in forward only

[kjp]

I have a G14 that only bucks "sometimes" in forward. Any ideas??

[golfcartg]

The FNR (forward / neutral / reverse) unit is known to be a weak link, so I would start by checking the contacts so that everything is in good condition. Examine the contacts for any signs of heat damage or melted connections which could indicate poor contact or excessive resistance. To do this, look for discoloration, warping, or any melted plastic around the contact points or burning smells. If you find any signs of heat damage, clean or replace to create a reliable connection.

Next, the motor brushes are responsible for conducting electrical current between stationary wires and moving parts, so if they are worn down or not making proper contact, the motor can exhibit intermittent power issues, leading to the bucking you described. Inspect the brushes for wear and replace them if they are less than a quarter inch in length. Additionally, check the brush springs to verify they are applying adequate pressure. The speed sensor, which monitors the rotational speed of the motor, can also cause similar issues if it is faulty. A malfunctioning speed sensor might send incorrect signals to the controller, causing irregular power delivery.

If everything checks out with the FNR unit, motor brushes, and speed sensor, then it’s time to look into the controller and throttle input potentiometer. The controller manages the power sent to the motor based on input from the throttle potentiometer. If either the controller or the potentiometer is malfunctioning, it can result in inconsistent power delivery, which might cause the bucking in forward. To test the throttle input potentiometer, use a multimeter to check for smooth resistance changes as you press the accelerator. If the resistance jumps erratically, the potentiometer may need to be replaced. Similarly, if the controller is not responding correctly to the throttle input, it may be defective and require inspection or replacement. Let me know how far you can get troubleshooting so we can proceed with the next steps.