A wiring harness (loom) carries every electrical signal on your motorcycle – ignition, lighting, charging, and starting. Because manufacturers revise connectors and wire routing almost every model year, buying the wrong loom is a common and frustrating mistake. This guide shows you how to match a replacement harness to your bike.
1. Start type is the first filter
Kick-start and electric-start (self-start) bikes use different harnesses. An electric-start loom includes wiring for the starter relay, starter motor, and usually a side-stand or neutral safety circuit. Buying a kick-start loom for a self-start bike leaves you with no starter circuit; the reverse adds unused plugs. Always confirm your bike start type.
2. Model year and BS emission version
Two bikes with the same name can use different harnesses across model years and emission norms (BS3, BS4, BS6). A 2010 Bajaj CT 100 loom is not the same as a 2017 CT 100B BS4 loom. The model year and BS version change connector counts and sensor plugs, so match both.
3. Connector type and count
Look at the main coupler that joins the harness to the CDI/ECU and to the meter. Count the pins. A mismatched pin count is the clearest sign you have the wrong loom. Product listings often state the connector type precisely so you can compare.
4. Brand-specific routing
Hero, Bajaj, TVS, Honda, Yamaha, Suzuki, and Royal Enfield each use their own routing, clip positions, and wire colours. Royal Enfield Bullet models, for instance, differ between right-hand and left-hand wiring. Never assume a universal loom will sit correctly – the length and clip spacing are designed for a specific frame.
5. Quality: copper, insulation, and connectors
A good harness uses multi-strand copper wire with heat-resistant insulation and properly crimped, not soldered-and-taped, terminals. Cheap looms fail at the connectors first. If you ride in wet or dusty conditions, look for looms with sealed couplers.
6. Installation tips
Photograph your original loom before removal, route the new harness along the same clips, and connect the battery last. Test lights, horn, and starting before final taping. Keep the old harness until everything works.
Bottom line
Match start type, model year/BS version, and pin count. Those three determine whether a harness is plug-and-play or a project.
Bike Model Fitment
| Bike Model | Year | Fits |
|---|---|---|
| Hero (Splendor Pro, CB Shine) | 2010-present | Yes |
| Bajaj (CT 100, XCD 125, Discover 150, Platina, KB4S) | 2004-present | Yes |
| TVS (Victor 110) | 2017-present | Yes |
| Royal Enfield (Bullet Machismo 350, Electra 350) | 2000-present | Yes |
| Suzuki (Zeus 125) | 2006 | Yes |
| LML (Freedom 125) | 2004-present | Yes |
Quick Mechanic Diagnostic Checklist
- Confirm kick-start or electric-start
- Note the model year and BS version (BS3/BS4/BS6)
- Count the pins on the main coupler
- Check right-hand vs left-hand routing for Royal Enfield
- Inspect connector quality and wire gauge before buying
- Photograph the old loom before removal
- Test all circuits before final taping
Frequently Asked Questions
What is the difference between a kick-start and electric-start wiring harness?
An electric-start loom adds the starter relay, starter motor, and safety-switch circuits. A kick-start loom omits them. They are not interchangeable without modifications.
How do I identify my bike correct harness?
Match the full model name, model year, BS version, and the pin count on the main coupler. If unsure, send us a photo of your existing harness and its connectors.
Can I fit a harness from a different model year?
Only if the connectors and routing match. Even one model year apart, manufacturers often change coupler types, so verify the pins before buying.
Are these harnesses genuine OEM?
They are OEM-spec looms made to the original routing and connector layout. The listing specifies the exact model, year, and start type.
Do I need any special tools to fit a wiring harness?
Basic hand tools, a test light or multimeter, and insulation tape are enough. No soldering is needed if the loom is plug-and-play.