Stuck with 48V to 12V golf cart conversion (I need help with key switch Connection)

Can anyone help me out here? I’m struggling to connect my key switch to a 48-12V reducer in my golf cart. I’ve tried a few things, but nothing seems to work. It’s really frustrating because I can’t use my lights or any 12V accessories. Has anyone successfully done this before?


I had a similar headache with my cart. Finally, I managed to solve it by using a SPDT switch for dual control. It was a bit tricky at first, but once I figured out the wiring, everything clicked into place. Connecting the thin red wire from the key switch to the SPDT switch was the key step for me.

Solutions that Worked for Users:

SolutionUsers Who Found SuccessApprox. Cost (USD)Approx. Time Needed (Minutes)
Use a SPDT Switch for Dual Control2$10 – $3030 – 60
Using a 12VDC @ 5amps or Higher Rated Switch1$5 – $2020 – 40
Wiring a Switch for the Voltage Reducer1$5 – $2020 – 40
Wiring Directly to the Key Switch1$0 – $1015 – 30
Using a DPST Switch1$10 – $3030 – 60


  • Difficulty switching from 48V to 12V in golf carts.
  • Inability to use 12V accessories like lights.

Possible Causes:

  • Incorrect wiring or connection of the key switch to the voltage reducer.
  • Inadequate switches or wiring that can’t handle the current.

Solutions that Worked:

  1. Use a SPDT Switch for Dual Control
    • What I Did: Connected the thin red wire from the key switch to one side of the SPDT switch.
    • Outcome: Enabled dual control for the converter.
    • Personal Experience: This setup provided flexibility and reliable control.
    • Steps:
      1. Identify and isolate the thin red wire from the key switch.
      2. Connect this wire to one terminal of the SPDT switch.
      3. Connect the middle terminal of the switch to the converter.
      4. Complete the circuit by connecting the remaining terminal to the thick red wire of the converter.
    • Expert Tip: Use a multimeter to check for continuity and correct voltage before and after installation. Ensure the switch is mounted in a location that is both accessible and protected from the elements.
  2. Using a 12VDC @ 5amps or Higher Rated Switch
    • What I Did: Chose a switch with a suitable rating.
    • Outcome: Efficiently managed the power distribution.
    • Personal Experience: This switch was effective and safe.
    • Steps:
      1. Select a switch rated for at least 12VDC @ 5amps.
      2. Connect the switch in line with the thin red wire from the converter.
      3. Secure the connections and mount the switch in a convenient location.
    • Expert Tip: Consider the environment where the switch will be placed. If it’s exposed to the elements, opt for a waterproof switch.
  3. Wiring a Switch for the Voltage Reducer
    • What I Did: Installed a toggle switch to control the reducer.
    • Outcome: Prevented battery drain effectively.
    • Personal Experience: This method was straightforward and effective.
    • Steps:
      1. Choose a suitable toggle switch that can handle the voltage and current.
      2. Install the switch between the battery and the reducer.
      3. Test the switch to ensure it effectively controls the power to the reducer.
    • Expert Tip: Regularly inspect the switch and connections for signs of wear or corrosion, especially in high-moisture environments.
  4. Wiring Directly to the Key Switch
    • What I Did: Directly connected the reducer to the key switch.
    • Outcome: Simplified operation with effective results.
    • Personal Experience: This method was the most straightforward.
    • Steps:
      1. Locate the key switch and identify the power input terminal.
      2. Connect the reducer’s power wire directly to this terminal.
      3. Secure the connection and ensure it’s free from obstructions.
    • Expert Tip: Check the key switch’s specifications to ensure it can handle the additional load. Overloading the switch can lead to failure.
  5. Using a DPST Switch
    • What I Did: Implemented a DPST switch for complete disconnection.
    • Outcome: Ensured no unintentional current flow.
    • Personal Experience: Provided a secure way to manage power.
    • Steps:
      1. Install the DPST switch in a location that’s easily accessible.
      2. Connect the switch to break both the positive and negative leads of the reducer.
      3. Test the switch to ensure it completely isolates the reducer when off.
    • Expert Tip: A DPST switch is particularly useful in setups where you want to ensure no power is drawn when the cart is not in use. This is especially important for carts that are not used regularly.

Golf Cart Models Where This Worked:

  • Club Car DS
  • Various models with similar electrical systems


Ernie loves documenting interesting facts about golf.

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