Golf cart potentiometers are electrical devices that send signals from the accelerator pedal to the controller to allow the controller to “detect” pedal position and adjust accordingly. There are many different types and we will discuss them, what they do, and how to test them.
As mentioned, the basic principle of golf cart potentiometers (PO-TENT-E-OM-METER) are to provide a signal to the electronic speed controller which in some way corresponds to the position of the accelerator pedal. They are generally electronic devices activated by depressing the pedal. The vast majority of golf cart potentiometers send a resistance signal measured in ohms to the controller. Some of the more common output signals are 0-5K ohms, 5K-0 ohms, and 0-1K ohms. For those of you not familiar with this vernacular, The “K” in the notation represents “times 1,000”, thus 5K is equal to 5,000. Further, a 0-5K ohms output would mean that full pedal up (not depressed), the golf cart potentiometer is sending a resistance signal of zero ohms to the controller. As the pedal is depressed, the signal rises accordingly and at fell pedal down to the floor, the output is 5,000 ohms to the controller.
E-Z-GO and Club Car used 0-5K ohms potentiometers in their early electronic speed controlled carts, but Club Car switched to a 5K-0 Ohms version in the mid 90’s and later to their MCOR (Motor Controller Output Regulator), while E-Z-GO moved onto their ITS version in the early-to-mid 90’s as well. Yamaha has used 0-5K ohms as ell as 0-1K ohms throttle outputs over the years.
In any scenario, the electronic speed controller must be perfectly matched to the golf cart potentiometer. The controller must have the same throttle input type as the golf cart potentiometer is sending, or at least the capability to be reprogrammed to another throttle type. For example, you cannot use a 5K-0 ohms controller with a golf cart potentiometer which outputs a 0-5K ohms resistance signal. The result would the opposite of normal. You would have full top end speed as soon as you press the pedal and you would actually get slower and slower as the pedal is depressed further. At full pedal down, you would stop.
Most of the resistance style golf cart potentiometers can be easily tested. Generally, there are two wires coming from the unit to the controller. Use an ohmmeter to test across those two wires, either at the controller or at the potentiometer. If you have a 0-5K ohms golf cart potentiometer, you would expect for the reading to be at zero and slowly progress to 5,000 ohms at pedal down position. If the reading is jumpy or erratic, or is out of range, you likely have a bad potentiometer.
There are also other styles golf cart potentiometers which output low voltage signals to the electronic speed controller. The signals are handled in the same manner as the resistance based style to adjust the speed based on pedal position. Some older Taylor-Dunn vehicles used a 6-10.5 volts output. E-Z-GO’s ITS (Induction Throttle Sensor) is a golf cart potentiometer that output a voltage based single to the controller.
Hopefully, our discussion about golf cart potentiometers has been informative. For specific testing procedures for your vehicle, always refer to your service manual.
By Michael Williams