How to Test/Install Golf Cart Voltage Reducer + (Wiring Diagram)

testing golf cart voltage reducer


What does a voltage reducer do on a golf cart? 

The purpose of a golf cart voltage reducer is to reduce the amount and strength of(voltage that goes into your battery. This will help prevent overcharging and damage to the batteries.


Voltage reducers have the following benefits:

  • Protect the batteries from failing
  • Voltage reducers distribute the voltage generated evenly throughout the cart.
  • A voltage reducer is a device that reduces the voltage of an electric current.
  • Converts the voltage of an alternating current (AC) source to a lower, more suitable level.
  • Voltage reducers are often used with small motors and like power tools, and golf carts.
  • Helps to reduce strain on the battery and extend its lifespan.
  • Reduces the voltage to a safe level for your golf cart.
  • Voltage is reduced by a factor of 2, 3, 4 or 5 depending on the model.
  • Used to run lights and sound systems off of a 12-volt battery.


Protects the batteries from failing

Voltage reducers can prolong the battery’s life, especially when adding golf cart lights or other accessories. When the battery charges, it helps to regulate and control the power sent to the battery.

If the battery sends out a high power output, the reducer limits the output. It draws out power evenly from the battery pack rather than using only some batteries at a given point in time. 

Without a voltage reducer, one or two batteries will die sooner than expected as they power the whole golf cart. Over a period, the overused batteries fail to recharge to total capacity and wear down gradually.

A typical golf cart will have a 48-volt or a 36-volt battery to power the golf cart’s lights and other electric accessories. The radio, CD, and tape players require only about 13.7 to 13.9 volts, which is reduced from 24, 36, or 48 volts by the voltage reducer. It generates a fixed output voltage irrespective of the input load conditions.


Do I need a voltage reducer for my golf cart? 

You need a voltage reducer for your golf cart if it is electric and has a battery with more than a 12V rating. The voltage reducer helps to power any 12V LED lighting accessory safely.

Make sure to find out your practical usage of the golf cart since this aspect is crucial in determining if the cart needs a voltage reducer. If you use it to get home for a 15 to 20 minutes drive from the golf course, you don’t need the voltage reducer.

You only require it if used for an extended period. However, it is always advisable to have a voltage reducer installed in your cart.


Testing the voltage reducer on a gas Club Car golf cart 

The voltage should not increase more than 14.5V when accelerating the Club Car golf cart since this is important for maintaining a long life for the battery. The voltage reducer ensures the same. Any reading above or below this value means that the voltage reducer is faulty. You have to keep in mind that the readings might differ based on the model of the cart.

A step-by-step method to test the voltage reducer on a gas Club Car golf cart is given below.

  1. Park the golf cart on an even and flat surface with wheel chocks on the front and back wheels so that the cart doesn’t move.
  2. Use a jacking kit to lift the cart after identifying the designated jacking point. This point should be somewhere below the frame on the back of the golf cart.
  3. Locate the batteries below the seat of the cart. 
  4. Connect the red probe of the voltmeter to the positive terminal of the battery. 
  5. Then connect black probe to the negative terminal of the battery.
  6. Set the voltmeter to 20V after turning it ON.
  7. Check the voltmeter reading without acceleration. If this reading is 12V, then it means that the battery is in good condition.
  8. Accelerate the golf cart and recheck the voltmeter reading. Ideally, it should show a reading between 14 to 16V. But if it still shows 12V, then there is a problem with the battery, and the reducer isn’t functioning correctly.


Testing the voltage reducer on a gas EZGO golf cart 

To test the voltage reducer on a gas EZGO golf cart, put the golf cart in neutral and activate the hand brake. If the voltmeter reading is between 14 to 16 volts, this means the voltage reducer is working. 

The steps mentioned below highlight how the voltage reducer of a 1992 model gas EZGO golf cart with a 350 CC 2 cylinder can be tested.

You can perform the first five steps mentioned above for testing the voltage reducer for a gas Club Car golf cart and then proceed with the steps given below.

  1. Put the cart in a neutral position with the handbrake activated. If the voltmeter reading is between 14 to 16 volts without pressing the forward pedal, then there is no problem with the voltage reducer. 
  2. If the above reading is below 14 volts, stop the golf cart and remove the wire connection above the starter generator.
  3. Connect the stud of the starter generator to a jumper and check the readings. If it’s above or equal to 15VDC, the voltage reducer is faulty.


Testing the voltage reducer on a Yamaha golf cart 

To test the voltage reducer on a Yamaha golf cart, check the reading on the voltmeter without accelerating the golf cart. If the reading is more than 15V, it means that the battery is overcharged.

If the voltmeter shows less than 13.5V without acceleration, ground the yellow wire of the reducer onto the starter generator and recheck the voltmeter reading. If the reading increases to between 17V and 18V, it indicates a problem with the voltage reducer.

Make a note of the voltmeter reading after the acceleration of the cart. If the reading is not 12.5V or close to this value, then the voltage reducer is faulty.


Where is the voltage reducer located on a club car golf cart?

The voltage reducer is placed below the seats and next to the battery of the Club Car golf cart.


Where is the voltage reducer located on an EZGO golf cart? 

The voltage reducer is found next to the battery and under the cart’s seat in an EZGO golf cart. The reducer is often wrapped in a black plastic shield with three wires coming out of it. 

The voltage reducer wires are red, green and black in color and shaped like a pyramid. The green wire is usually connected to the starter generator in the front.


Where is the voltage reducer located on a Yamaha golf cart? 

The voltage reducer is located under the cart’s seats and adjacent to the battery in a Yamaha golf cart.


EZGO voltage reducer wiring diagram 

The EZGO voltage reducer wiring diagram illustrates how to connect a voltage reducer to your EZGO golf cart.

The voltage reducer should be placed on a solid metal frame. There must be enough space surrounding the voltage reducer for its wiring to have no mechanical interference.

A 5/16-inch ring terminal is connected to the negative post, negative standoff stud, or the sixth battery’s B-terminal. The grey wire featuring a 0.250 female FASTON is connected to the 12-volt accessory terminal board or negative circuitry. The 12V lead wire from the positive post of the fifth battery is connected to a 25amps fuse.

Click here to see the EZGO voltage reduce wiring diagram


Club Car voltage reducer wiring diagram

The wiring diagram of the voltage reducer for a Club Car varies slightly depending on whether the cart uses a four-wire reducer or a three-wire reducer.

A four-wire reducer has black, yellow, brown and red colored wires. If this type of reducer is used, its black wire is plugged into the microswitch. The black wire with the ring terminal is connected to the solenoid. The yellow wire of the reducer is connected to the DF terminal. Similarly, the brown and red wires of the voltage reducer are connected to the F2 terminal of the starter generator and the sixth white terminal of the solenoid, respectively.

On the other hand, a three-wire reducer comes with red, yellow, and black wires. The red wire of the reducer is connected to the terminal of the starter solenoid. The yellow wire is connected to the starter generator, while the black wire is connected to the ground connection.

Click here to see the Club Car voltage reduce wiring diagram


Bad Voltage Reducer Symptoms 

Voltage reducers tend to wear down with time. The list given below highlights some of the most common symptoms associated with a bad voltage reducer:

  • Electric systems such as dashboards and headlights show signs of problems by dimming.
  • Parts of the golf cart like fuel pumps or ignition systems may not work as expected.
  • The terminals and top of the batteries start getting corroded, and this corrosion spreads to nearby parts as well.
  • One or more batteries will drain and die out since the voltage reducer fails to even out the battery output.
  • The engine will depict one or more faulty signs such as intermittent acceleration, spluttering, and stalling.
  • The instrument cluster of the cart behaves erratically or stops working completely.
  • The voltage reducer shows inaccurate readings.
  • The batteries indicate high voltage outputs.
  • The indicators for engine light or battery light may turn ON erratically.


Club Car voltage reducer problems 

Overheating and blowing up the fuse are the most common problems associated with a Club Car voltage reducer. These problems can be eliminated by connecting all the terminals tightly and adequately. You must also make sure to leave enough gaps between the wires to eliminate the back-feeding problem. Ideally, a positive ground follows an input, ground, and output pattern, while a negative ground follows the ground, input, and output pattern.


EZGO voltage reducer problems 

The primary concern with an EZGO voltage reducer is overheating. This can be eliminated by ensuring that the voltage reducer wiring design has been correctly implemented and the starter belt of the generator is loose enough not to get strained. 


How to install a voltage reducer on a golf cart  

A faulty voltage reducer causes problems with the motor of your cart. Furthermore, it can lead to other problems such as overcharging of electrical components, which results in them burning out.

Moreover, a faulty voltage reducer prevents a golf cart battery from retaining its charge.

You should wear a pair of gloves and safety glasses while installing the voltage reducer. The following steps guide you on installing a new voltage reducer in your golf cart in place of the old faulty one. 


  1. Locate the battery hatch cover under the cart’s front hood or below the seat and open it. Most carts have six 8-volt batteries.
  2. Remove one of the cables connected to any of the battery terminals. You can disconnect the positive or negative terminal of any battery. It’s essential to do this disconnection so that the voltage reducer can be installed safely without the risk of electric shock. Ensure that you don’t touch any other battery component other than the nut you plan to unscrew for the disconnection.
  3. Connect the B-terminal of the voltage reducer to the negative terminal of the first battery.
  4. Connect the +12-volt terminal of the voltage reducer to an accessory’s hot wire such as a radio or a light. The hot wire is generally red.
  5. Connect the -12-volt terminal of the voltage reducer to the same accessory’s ground wire. The ground wire is generally black.
  6. Reconnect the cable disconnected earlier in Step 2.
  7. Put the front hood or seat back in place and keep the cushion in its position over the cart seat.


How to Fix a Bad Voltage Reducer on a Golf Cart  

The fixing process of a bad voltage reducer depends on the reason and the root cause why it’s not working. Some ways to fix a bad voltage regulator are given below.

  1. Remove the wire connection from the reducer to the starter generator. This connection generates up to 18V output, which is bad for reducers and batteries, causing them to overheat.

  2. Remove the yellow wire connected to the ground from the starter generator as it results in maximum current flow in the field coil of the starter generator. This affects both the starter generator and battery, which prevents the voltage reducer from functioning correctly.


Ernie loves documenting interesting facts about golf.

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