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// SR Lab // Log #001 // Hands-On DIY Tested

Hazard Light Mod

HAZARD LIGHT RETROFIT // CLEAN WIRING // DIY VERIFIED


SR Lab Log #006

Most bikes in Singapore don't come with factory hazard lights. This mod adds that function — both sides flashing simultaneously — using a simple relay and switch setup.

The Problem With No Hazards

Stock bikes often lack a hazard light function. When you're broken down by the roadside, you can't flash both sides simultaneously to warn other road users. This mod fixes that. It's a safety feature that should be standard — and frankly, in Singapore traffic, it's essential.

This was also the mod that first got me into DIY. Finding out that a workshop wanted to charge a few hundred bucks for what is essentially a $10 parts job — that was the wake-up call. I never looked back.

How It Works

Concept
Bridge both turn signal outputs through a relay, triggered by a standalone switch
Step 1
Identify the left and right indicator power wires at the handlebar switch cluster
Step 2
Install a SPST momentary or latching switch in an accessible position
Step 3
Wire the relay: coil triggered by switch, contacts bridge both indicator lines
Step 4
Tap relay power from the battery via an inline fuse (5A recommended)
Step 5
Test both individual indicators still work — then verify hazard mode engages

Parts Required

// Bill of Materials
  • 12V 4-pin or 5-pin automotive relay (SPST or SPDT)
  • Relay base / harness
  • Latching toggle switch or momentary push button
  • Inline fuse holder + 5A fuse
  • Wire, connectors, heat shrink, zip ties
// IMPORTANT: Do NOT splice directly into the indicator wires without a relay. The relay isolates your new circuit from the OEM wiring and protects the factory flasher relay from overload. Always fuse your added circuit.

Real World Notes

Once you understand relays, this mod becomes straightforward. The trickiest part is finding a clean place to mount the switch where it won't interfere with normal handlebar operation. I mounted mine under the instrument cluster — out of sight but reachable in an emergency.

Workshop quote for this mod: Several hundred dollars. Actual parts cost: Under $15. That gap is what pushed me deep into DIY territory.

Detailed Field Notes: Hazard Mod

Mod Classification: Electrical / Safety

[RELAY LOGIC] The relay coil draws very little current from your switch. The heavy indicator load flows through the relay contacts, not through your new switch wiring. This keeps everything clean and protected.

[FLASHER COMPATIBILITY] If your stock flasher relay is load-sensitive (common on older bikes), switching to an LED-compatible or heavy-duty flasher unit first will prevent irregular flash rates when both sides are on simultaneously.

[SWITCH PLACEMENT] Accessibility matters. In an emergency you need to activate this fast. Practice reaching for it blindly so muscle memory kicks in when you need it most.

Final Assessment
  • Difficulty: 3/5 — Relay wiring logic takes some understanding
  • Time Required: ~2 hours
  • Would Recommend: Essential safety mod for all riders