Tuhorse Well Pump Wire Splice Kit, Submersible 3M Dual Wall Heat Shrink Tubing and Copper Connector for 4 Wires, #10#12#14 AWG.

Why I reached for this kit

A failed splice on a submersible pump cable is one of those problems you only want to fix once. I pulled a 1/2 HP deep well pump recently to chase an intermittent fault and found a tired connection where the drop cable meets the motor leads. I wanted a clean, inspectable, and truly watertight splice without mixing epoxy or wrestling gel packs in a cramped pit. That’s what led me to the Tuhorse splice kit.

What’s in the box

The kit is simple and complete for a four-conductor splice:
- Four clear, dual-wall heat-shrink sleeves with adhesive lining (3M tubing)
- Four pure electrolytic copper butt connectors sized for #10–#14 AWG conductors

No extras, no filler. The clear tubing is the standout—being able to see the crimped copper and watch the adhesive flow is a genuine advantage when the splice’s life depends on a tight seal. All components are made in the USA, including the 3M tubing, which is reassuring for a critical, submerged connection.

Build quality and first impressions

The copper barrels are nicely machined and took my #12 AWG pump cable cleanly with a snug fit—no slop. The tubing wall is thicker than the generic shrink sleeves you find in multipacks; the inner adhesive liner is uniform and not messy. Out of the package, everything looked and felt like a purpose-built solution rather than a rebranded generic.

Because the tubing is clear, there’s no color coding, and the connectors aren’t color-banded either. That’s fine for pump work (four wires, four splices), but it does put the onus on you to identify conductors diligently before cutting and stripping.

Installation experience

I used this kit to splice the pump motor leads (three conductors plus ground) to a drop cable, both #12 AWG copper. The process was straightforward:

1. I cut back to bright copper and stripped insulation to match the butt connector barrel length, leaving a hair less so the insulation butts up tight when inserted.
2. I slid a heat-shrink sleeve over one side of each conductor before making any crimps.
3. Using a ratcheting crimper with the correct die for non-insulated butt connectors, I made two compressions per side, checking for a slight “witness mark” without deforming the barrel.
4. I gave each crimp a firm pull test. If it moves, start over—there are no spares in the kit.
5. I centered the clear 3M sleeve over the joint and applied heat, starting in the middle and working outward toward the ends.

I used a variable-temperature heat gun for most of the shrinking and tried a brief pass with a small propane torch on one sleeve as a stress test. Used carefully, both worked. The tubing remained clear, didn’t char, and the adhesive flowed visibly along the copper and squeezed out as a continuous bead at both ends—a good visual cue that the seal is complete. The transparency is not a gimmick; it makes it easier to confirm a proper crimp and that the adhesive has filled voids.

The finished splices were compact, smooth, and uniform. No cold spots, no gaps, and no trapped air pockets I could see.

Watertightness and durability

For peace of mind before dropping the pump back, I dunk-tested the cable assembly in a bucket and flexed the splice area while heating and cooling the water. The sleeves showed a continuous adhesive ring and didn’t weep or bubble. After installation, the pump ran under normal duty with no hint of moisture-related resistance changes when I checked continuity after a few cycles.

Over a few weeks, I pulled the pit cover twice to inspect for wicking or signs of migration past the sleeve ends—everything stayed bone dry. The outer surface of the tubing is tough enough to handle routine handling and lowering without scuffing, but like all heat-shrink splices, it’s not an abrasion jacket. If you expect to slide along sharp edges or scrape through rocky casing, add a secondary protective wrap or split loom over the splices.

What stood out

• The clear 3M dual-wall tubing is excellent. Seeing the crimp and adhesive flow removes guesswork, which matters when the splice lives underwater.
• The adhesive liner wets out evenly and creates a confident seal. The “bead at the ends” visual is a useful go/no-go indicator.
• The copper butt connectors crimp cleanly and hold tight without distorting. After a proper crimp, the pull test inspires confidence.
• The kit is sized exactly for typical submersible pump conductors (#10, #12, #14 AWG) and includes four sleeves/connectors for a three-wire-plus-ground setup.
• USA-made components are a nice touch for a critical connection.

What I’d change

• No spares. Four connectors and four sleeves mean you need to get every step right on the first try. One or two extra sleeves would make the kit more forgiving.
• No labeling or conductor IDs. The clear sleeves are great for inspection but don’t help with wire identification. Plan your markings before you cut.
• The kit doesn’t include strain relief or abrasion protection. That’s normal for heat-shrink splices, but be ready with additional sleeving if your installation needs it.
• Bring your own tools. You’ll need a proper non-insulated crimper and a heat gun or cautious torch technique; pliers and a lighter won’t cut it here.

None of these are dealbreakers, but they’re worth knowing so you can prep accordingly.

Practical tips for best results

• Clean copper only. If the wire is oxidized or tinned, cut back to bright copper. Don’t use dielectric grease inside the splice; it can interfere with the adhesive bond.
• Measure the strip length against the barrel and avoid over-stripping. You want insulation tight to the barrel edges to minimize voids.
• Use a ratcheting crimper with the correct die for non-insulated butt connectors. Two crimps per side on #12 gave me the best bite.
• Heat from the middle outward and keep the heat moving. Watch for uniform shrink and a consistent adhesive bead at both ends of the sleeve.
• Stagger splices along the cable if you have room. It reduces the overall lump and makes the assembly more flexible.
• Label conductors before cutting. With clear tubing, you won’t have color cues once you’re done.

How it compares

Resin or gel-filled splice kits certainly work for submersible applications, but they’re bulkier, messier, and not easily inspectable. Solder-seal heat-shrink connectors can be convenient, but I prefer a mechanical crimp in pump applications where vibration and thermal cycling are routine; a well-executed crimp keeps the conductor strands intact without a brittle solder joint. The Tuhorse splice kit lands in the sweet spot: clean, compact, inspectable, and purpose-built for underwater duty.

Who it’s for

• DIY well owners who need a reliable repair without specialty potting compounds.
• Pump installers who want a quick, repeatable, and inspectable splice for #10–#14 AWG.
• Anyone repairing direct-burial cable in wet locations, from landscape lighting to outbuildings, where a watertight butt-splice is appropriate.

If you’re working with aluminum conductors, larger gauges, or need a splice rated for significant mechanical strain, look elsewhere—this is a copper, light-to-moderate strain solution.

Bottom line and recommendation

The Tuhorse splice kit does exactly what I want in a submersible pump connection: it delivers a tight, inspectable crimp and a clear, adhesive-lined seal I can trust underwater. Installation is straightforward if you have the right crimper and a steady heat source, and the finished splice is compact and tidy. I’d appreciate a spare sleeve or two, and I wish the kit included optional abrasion protection, but those are minor asks.

I recommend this kit for anyone needing a dependable splice on #10–#14 AWG copper conductors in wet or submerged environments. The combination of quality 3M dual-wall tubing, solid copper connectors, and the clarity that lets you verify your work makes it a strong, confidence-inspiring choice for pump leads and other waterproof applications.