How to Test & Install a Golf Cart Voltage Regulator (Steps)

What Does a Golf Cart Voltage Regulator Do?

A golf car voltage regulator is one of the most important parts of a golf cart. The voltage regulator helps to limit and regulate the power that is sent to a golf cart battery for its recharge.

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When you start your golf cart, the starter generator performs the role of a starter motor and causes the engine to start. However, when the internal combustion of the engine begins, the generator begins to perform its actual function. The combustion triggers the generation of power to be sent back to the battery.

Often, the speed variations of the engine cause the power flow to be erratic and irregular. This fluctuation can be very detrimental to the life of your golf cart battery.

To ensure the long life of the battery, you will need a steady voltage flow. A voltage regulator can help you in achieving a constant steady flow of power.

Most of the time, a voltage regulator makes sure that the recharge voltage never goes above 14.5 volts. It helps in recharging the battery while ensuring its long life by offering a constant and smooth voltage.

There are various types of voltage regulators in the market for different models of golf carts. Bosch and Hitachi are two well-known brands for reliable voltage regulators.

Where is the Voltage Regulator Located on a Golf Cart?

The voltage regulator in a golf cart is often found under the cart seat; near the battery. It is generally quite small and compact.

How to Test a Golf Cart Voltage Regulator

Most electric golf carts use 12-volt batteries for their operation. As the name indicates, a voltage regulator is capable of controlling the voltage flow that returns from the magneto. As a result, the batteries experience a backflow of a constant voltage of 14 volts.

Malfunctioning of the voltage regulator causes a restriction to the current flow to the batteries. This causes the batteries to start draining faster than usual.

There are also instances when the batteries tend to get overcharged. Overcharged batteries eventually get damaged.

To avoid the above problems, it’s recommended that you check the voltage regulator of your golf cart regularly. This is not a time-consuming process and takes just about 10 minutes to get done. You might consider checking your battery before the voltage regulator.

The following steps offer guidance on how to check a battery followed by checking the voltage regulator.

Park the golf cart on a level, hard surface and activate the parking brake. You might want to additionally keep wheel chocks before the front tires so that the cart does not roll forward.
Keep a jack below the frame at the back of the golf cart. Position the jack stands below the frame behind the back tires and elevate the cart.
Lift the golf cart seat upwards until the batteries are exposed.
Turn on the voltmeter and set the reading to 20 volts. Connect the red lead of the voltmeter to one of the positive posts of a battery. Similarly, connect the black lead of the voltmeter to the negative post of this battery.
Check the voltage reading on the voltmeter. If the reading is 12volts, it’s a clear sign that the battery is in good condition.
Release the forward control pedal keeping the voltmeter connected at the same time.
Check if the voltmeter reading is between 14 volts and 16 volts. If it continues to be 12 volts, it indicates that the voltage regulator is faulty.

Testing the voltage regulator on a gas Club Car

You can follow the steps given below to test the voltage regulator of your gas club car.

Connect the voltmeter to the battery and get the golf cart running. You can consider applying the hand brake to prevent rolling.
Check if the voltage rating is between 14 volts and 16 volts. If it’s less than this range, remove the wire above the starter generator after stopping the cart.
Use a jumper and connect it from the ground of the cart to the stud of the starter generator. If the voltage is 15VDC or more, then the voltage regulator is faulty.

Testing the voltage regulator on a gas Yamaha golf cart

Remove the drive belt from the golf cart. You can also consider turning off the engine of the cart so that there is no movement.
As mentioned above, connect the voltmeter to the battery and check the voltage reading. If it’s above 15 volts, it’s a sign of overcharging.
Release the pedal and check if the reading is 12.5 volts or just above this value. If it’s not so, the voltage regulator may be at fault.
Alternatively, if the above battery voltage in Step 2 is less than 13.5 volts, ground the yellow wire present on the starter generator to the chassis.
If the voltage reading increases to 17 volts or 18 volts, it indicates a faulty voltage regulator.

How to Test a 4-terminal automotive-style voltage regulator on a Yamaha golf cart

Disconnect the harness connection on the voltage regulator and jump the first and third terminals.
Connect a voltmeter to the battery of your golf cart and get the cart started. If the voltage reading is above 13 volts, there is a problem with the voltage regulator.

If you have a plug-in style regulator, you can jump it with the help of paper clips if needed.

How to Install Voltage Regulator on a Golf Cart

Installing a voltage regulator in your golf cart often becomes necessary when you experience any problem with the motor of your golf cart. In most cases, a motor problem is likely to be due to a faulty voltage regulator.

Having a faulty voltage regulator can lead to other problems as well, such as overcharge causing electrical components to burn out or inability of the golf cart battery to retain a charge. From my own experience, you should replace your voltage regulator as soon as possible!

For your safety, you should wear a pair of work gloves and safety glasses when you make the replacement. You will have to keep a few simple tools handy to help with the replacement. The process may vary slightly depending on the make and model of your golf cart.

The steps mentioned below will guide you on how to replace a faulty voltage regulator.

Open the battery hatch cover that is usually located below the front hood or under the golf cart seat.
Loosen and remove the negative cable of the battery that is connected to the battery charger directly. Use a wrench for disconnecting the cables.
Remove the negative cables of all other batteries as well, in the same way.
Now remove all the positive cables from the batteries.
Disconnect the voltage regulator from the battery so that it can be removed. In some cases, the regulator may be bolted or latched on to the golf cart. Use the appropriate tool and disconnect it.
Put the new voltage regulator in place and fix the bolts or latches in place.
Connect a voltmeter to the poles of the battery and start the engine of the golf cart. Make sure that there is no spin. The voltage should typically be 12.6 volts.
Raise the speed of the golf cart engine. The voltage will also increase accordingly until the speed is nearly 1,000RPM. After this, the voltage remains steady at 13 volts with a +/-0.5 volts difference.
Check the electrolyte levels in each battery and top up to the required level using distilled water if needed.

EzGo Golf Cart Voltage Regulator Location

The voltage regulator of your golf cart is usually located under the cart seat along with the batteries. It’s fitted in place using latches or bolts.

In an EzGo golf cart, the voltage regulator is often located inside a black plastic shield that is shaped like a pyramid and has three wires of different colors. The wires are red, green, and black. The green wire is connected to the starter generator on its front side.

Voltage Regulator Wiring Instructions

Two types of voltage regulators are commonly used. One type makes use of three wires while the other type comes with four wires. Irrespective of the kind of voltage regulator that you opt for, it’s essential that the wires of the voltage regulator in your golf cart are connected correctly.

Incorrect connections can do more harm than good. Such a connection will not only affect the voltage regulator but also other components of the golf cart. The actual wiring may differ depending on the type of voltage regulator that you use in your cart.

The following tips are a general guideline for getting the wiring of your voltage regulator right.

If you’re using a four-wire regulator in a gas club car, a black wire is to be connected or plugged to a micro-switch. You must hook the other black wire with a ring terminal that is bolted to the bottom of the voltage regulator along with other wires to a solenoid.
The voltage regulator has a yellow wire that is connected to the DF terminal of the starter generator and a red wire that is hooked to the sixth white terminal of the solenoid. The brown wire is connected to the F2 terminal of the starter generator.
In a Pioneer club car that uses a three-wire voltage regulator with red, yellow, and black wires, the yellow wire must be connected to the starter generator and the black wire connection should be made to the ground terminal. The red wire should be connected to the terminal of the starter solenoid that has all the white wires.

Voltage Reducer Wiring Diagram Explained

The steps given below to install the voltage reducer of a golf cart will give you an explanation of its wiring diagram.

Place the voltage reducer on a solid metal frame. Use only metal frames and avoid plastic because of the heat dissipation capability of the regulator. Maintain a clearance of two inches from nearby components.
Ensure that there are no mechanical interferences and that there is enough space for wiring.
Confirm that the battery pack has a set of 8VDC batteries only. A voltage reducer is often intended for use with two 8 volts batteries.
Connect the 5/16-inch ring terminal to the sixth battery’s negative post, B-terminal on the speed controller or the negative standoff stud.
Connect the grey wire that has a 0.250 female faston to the 12 volts negative circuit directly or the 12 volts accessory terminal board.
Connect a 25 amps fuse with fast-acting property to the 12 volts positive lead wire that is connected to the fifth battery’s positive post.

If you’re planning to use a fuse block, connect the +12 volts positive wire to the fuse block and do all the connections from there. You must not choose the chassis of the golf cart for ground wire connections.

It’s a good idea to use a distribution block for negative feeds or for connecting the negative terminals of all the accessories.

Why is My Voltage Regulator Overheating?

Some reasons why the voltage regulator of the golf cart is getting overheated could be as follows.

Improper pin connections are one of the most common reasons for your golf cart voltage regulator to get overheated. Positive ground regulators should have the pins in the order of input, ground, and output from left to right. For negative regulators, the order is ground, input, and output.
The regulator circuit does not encompass bypass capacitors. There should at least be a capacitor with short leads as close as possible to the device from the input to the ground pin.
The regulator design has not been implemented properly and the absolute maximum rating has been exceeded.
The starter belt of the starter generator is very tight without any deflection resulting in it getting strained. This makes the voltage regulator get heated up.

How to Fix a Bad Voltage Regulator on a Golf Cart

There are many reasons for the voltage regulator in your golf cart to not behave as expected. Depending on the reason, the fixing process varies accordingly. Some fixes are given below.

Remove the grounding of the green wire from the voltage regulator to the starter generator. This wire is responsible for controlling the regulator. When it gets grounded, the maximum output becomes 18 volts, which is bad for the regulator.
Remove the grounding of the yellow wire coming from the starter generator to the ground. This causes maximum current flow through the field coil present in the starter generator. This is bad for both the battery and starter generator that in turn affects the proper functioning of the voltage regulator.

You can also follow the steps given in the section ‘How to install a voltage regulator on a golf cart’ above to replace a faulty voltage regulator.

Bad Voltage Regulator Symptoms

The following are some symptoms which indicate that you probably have a bad voltage regulator on your golf cart:

The external systems like dashboard elements and headlights start pulsating or dimming because the alternator will not be able to cycle sufficient power from the battery.
One or more batteries are dead because of a burned-out voltage regulator that lessens or stops its charging capability.
The engine experiences problems like spluttering, stalling or intermittent acceleration because the voltage regulator is not capable of handling the power generated by the alternator.
The instrument cluster doesn’t work due to damage to the voltage regulator.
The readings of the voltage regulator are inaccurate and the numbers displayed on the gauge keep changing erratically.