Series Wiring LED Marker Lights – Why Instructions Matter

Series wiring LED marker lights is very different from wiring standard 12V or 24V lighting.
Many outdoor marker lights are designed specifically for series wiring and must be powered by a constant current LED driver.

Failing to follow the manufacturer’s instructions — especially wiring series-rated lights in parallel — can result in permanent LED damage.

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What Does Series Wiring Mean for LED Marker Lights?

In a series wiring LED marker lights installation, each light is connected end-to-end, forming a single electrical path.

In this type of circuit:

• The same current flows through every fitting
• The driver controls the current (typically 350mA or 700mA)
• The voltage is shared across all lights

If one light fails or is disconnected, the circuit opens and all lights turn off. This is normal behaviour for series wiring.

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Why Series Wiring LED Marker Lights Require Constant Current Drivers

Series-wired marker lights are current-controlled, not voltage-controlled.

They must be powered by a constant current LED driver, not a 12V or 24V constant voltage supply.

Common ratings include:

• 350mA – lower output marker and step lights
• 700mA – higher output wall and marker lights

The driver automatically adjusts its output voltage to suit the total load of the series circuit.

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⚠️ Important Warning: Parallel Wiring Will Damage Series Lights

If series wiring LED marker lights are connected in parallel:

• The LEDs receive uncontrolled current
• Internal overheating occurs
• Brightness becomes unstable
• LEDs may fail instantly or degrade over time

Even if the lights appear to work initially, irreversible internal damage may already be happening.
This type of damage is usually not covered by warranty.

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How to Wire LED Marker Lights in Series (Correct Method)

The correct method for series wiring LED marker lights is:

1. Connect the constant current driver output to the first light
2. Link each light out to in, end-to-end
3. Connect the final light back to the driver
4. Use only identical fittings on the same circuit

Always confirm the total forward voltage of all lights falls within the driver’s voltage range.

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Common Installer Mistakes to Avoid

❌ Assuming all low-voltage lights can be wired in parallel
❌ Using a 12V or 24V constant voltage power supply
❌ Mixing 350mA and 700mA fittings on one circuit
❌ Adding extra lights without recalculating total voltage

Marker lights may look similar externally, but their electrical requirements can be very different.

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Best Practice Before Installation

Before installing any marker lights:

✔️ Read the manufacturer’s instructions
✔️ Confirm whether series wiring is required
✔️ Match the correct constant current driver
✔️ Verify the current rating (350mA or 700mA)
✔️ Calculate total circuit voltage

Never assume wiring method based on appearance alone.

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FAQs – Series Wiring LED Marker Lights

Can I wire series LED marker lights in parallel?

No. Series wiring LED marker lights must not be wired in parallel. Parallel wiring removes current control and can permanently damage the LEDs.

What happens if I wire series lights in parallel by mistake?

The LEDs may:
Overheat
Flicker or dim unevenly
Fail immediately or prematurely
Even short-term testing can cause long-term damage.

Do all marker lights require series wiring?

No. Some marker lights are designed for parallel wiring, others for series wiring. Always check the product instructions before installation.

What driver do series LED marker lights need?

They require a constant current LED driver, typically rated at 350mA or 700mA, matching the fitting specification exactly.

Is it normal for all lights to go out if one fails?

Yes. In a series circuit, one failed or disconnected light opens the circuit and turns all lights off.