You've got the mo.unit blue in hand. The parts are on the bench. You're ready to go — except you realize you've never actually crimped a wire before. Or you have, but you're not sure if you did it right.
This is Part 3 of our comprehensive mo.unit blue installation series. In Part 1, we covered the complete motogadget shopping list and project overview. In Part 2, we prepared the wiring harness and created the wiring plan. Before we get into Part 4 and start making real connections, we need to talk about the motorcycle wiring techniques that make or break a clean install.
This post is based on the second part of our motogadget installation series on YouTube:
What we'll cover in Part 3:
- How to Use Flat and Round Connectors
- How to Solder Wires
- How to use heat shrink
- How to use Molex Mizu P25 connectors (and similar!)
- How to crimp battery lugs and ring terminals
- How to connect wires to mo.unit with wire ferrules
Crimping: The Technique You'll Use Most Often
Most of your connections in a mo.unit blue install will be crimps. Turn signals, switches, ring terminals to the battery — crimping is faster than soldering and just as reliable when done correctly.
Two things are crucial:
- Match the terminal to the wire gauge. Too big and terminal can’t properly squeeze down on the wires. Too small, and of course, it won’t fit. As small as possible, as big as necessary.
- Use a proper crimping tool. A ratcheting crimper costs $20–40 and ensures consistent crimps. Pliers, or worse yet, a flat head and a hammer, are a no-go.
Soldering: For Permanent Joints
There’s a time and place for crimping, and there’s a time and place for soldering — joining wires mid-run, extending a factory harness, anywhere you need a clean and permanent connection with no bulk – it’s time for solder.
Heat the wire, not the solder. When the wire is hot enough, the solder flows in on its own. If it globs, looks dull, or you can feel it shift when it cools — that's a cold joint. Cold joints fail. Redo it.
Always seal it with heat-shrink tubing. Speaking of which...
Heat shrink: not optional for motorcycle wiring
Heat-shrink protects your work from moisture, vibration, and abrasion – but most importantly, it keeps the flowing current inside the cable and not on you or the bike. A bare wire is just asking for a short in the system. There are both adhesive-lined and non-adhesive heat-shrink tubing available. Tip: In the mo.unit Ultimate Builder Pack includes self-adhesive ones.
Heat shrink is simple, but the main “face-palm” you’ll run into is not first running a piece of heat shrink over the wire before closing the connection. If you can avoid that problem, all you need is a heat gun to finish the job. Just try not to melt anything.
Ferrules: Specific to the mo.unit blue
The mo.unit blue uses push-in terminals. You can insert bare wire ends directly. But there are better ways.
Raw stranded wire fans out when it enters a terminal, making inconsistent contact that gets worse over time. Ferrules solve this — they're small metal sleeves that crimp onto a stripped wire end, bundling the strands into a solid tip.
What you'll need:
- A a ferrule crimper (square-profile, not the same as your terminal crimper)
- A mixed ferrule kit to match your wire gauges
- About 30 seconds per cable
Install of the wire ferrule will feel very similar to crimping anything else. Just make sure you have bare wire inside the whole ferrule tube, but not sticking out the end. You’ll know if you used too big a wire ferrule if, after crimping, it's this ragged, breakable mess. When the ferrule has something to squeeze onto (your wire), it doesn’t “accordion” as much.
Using a multimeter for motorcycle wiring
You can really get away with knowing two functions of a multimeter:
Continuity — is this circuit complete? Use this to trace a wire, confirm a switch works, or verify a ground connection.
Voltage — what's actually happening at this point in the circuit? Use this before and after your install to confirm everything is behaving as expected. Important note regarding mo.unit outputs: The mo.unit’s outputs cannot be measured directly—without a connected load, the multimeter will not display any usable results. To test an output, connect a load (e.g., a light bulb) and then measure the voltage.
That's it. Those two functions will handle 90% of the situations you'll encounter. Spend 15 minutes with a multimeter before you start, and you'll feel a lot more confident when something doesn't work the first time. And something won't work the first time.
Practice before you commit
Grab some scrap wire and a few terminals. Do five crimps. Try a solder joint. Shrink some tubing. It sounds unnecessary until you're on your actual bike with your actual harness and your actual confidence level matters.
Golden Rule: The bench is the place to make mistakes. Not the motorcycle.
What happens next
Part 4 is where the mo.unit blue actually goes in. We'll be connecting wires, integrating the system into the remaining original components, and making the magic happen — with all of the above techniques in play.
Until then—follow motogadget on YouTube, Instagram, and TikTok for quick tips and short clips between episodes.
- Jacob Baldry, for motogadget
