You don't need to worry about a twist between the wires when you combine the wires. All kinds of standard test probes can be used to check the lever nut. There is a test hole at the back of the lever nut and the hole are designed to check whether the wires have electricity or not.
eBay
100/50/10Pcs Yellow RV5.5 M4-M8 Ring Crimp Terminal 12-10AWG Insulated Electrical Cable Wire Connector
Aliexpress UK
[Easy to Use] Our power drill wire stripper cutter tool can be used with hand drill and electric tools, which is quick wire stripping. It is not just a wire stripper, but a screwdriver. [Quick Wire Stripper] With the electric drill, the wire sheath will be rotated out along the groove of the wire stripper.
eBay
9A 250V AC 3 Pin IP44 Waterproof Electrical Cable Wire Connector Junction Box top sale
Aliexpress UK
Type2 Heat Shrink Connectors. type3 Heat Shrink Solder Connectors. type4 Solder Seal Wire Connectors. wire range 0.5-1.5mm²(AWG 22-18). Compatible wire：0.5-1.5mm²(AWG 22-18). Light in weight.Durable in use，Easy to install，Very convenient and practical.
eBay
10/50/100Pcs M4/M5/M6/M8/M10/M12 Ring Crimp Terminal Insulated Electrical Cable Wire Connector 12-10AWG
Aliexpress UK
Conductor of wire is not exposed during connection. No need to strip insulation before connection. Workable Wire Type: Solid wire/Strand wire 22-18# AWG. No need to twist nor tape the conductor. (4) Local pick up is not available.
eBay
10/50/100Pcs/Lot M4-M12 mix RV2 M4/m5/m6/m8/m10/m12 16-14AWG Ring Crimp Terminal Insulated Electrical Cable Wire Connector
Aliexpress UK
2/3 way super-sealed waterproof wire connector. Sealed waterproof connector. 1 X male connector housing and insert;. 1 X female connector shell and insert;. Silicone rubber connector seals;. 10 sets of plug connectors (not including cables).
eBay
IP68 Waterproof 3 Way Electrical Cable Wire Connectors LED outdoor junction box Line Protection for Wiring Accessories
Aliexpress UK
Just insert the wires into the electrical connector. The squeeze the blue cap by a crimping tool. Easy to Use - Just insert the wires into the electrical connector. 25 pcs 3 wire connectors. Connector type: Custom Connector.
eBay
1PC 2 Way IP66 Outdoor Waterproof Electrical Cable Wire Connector Junction Box With Terminal 450V Junction Box For Led Light
Aliexpress UK
Works perfectly with caravans, trucks, RV, boats and trailers. 3 Pin Waterproof Connector,Silicone Waterproof rubber gasket. and high quality IP68 connector. 3Pin connects tail, brake, reverse, turn signals, brakes and auxiliary power.
eBay
IP68 Waterproof Junction Box 2-4 Way LED Outdoor Boxes Electrical Cable Wire Connector Line Protection For Wiring Accessories
Aliexpress UK
3Pin Waterproof Junction Box IP68 Cable Gland Connector Electric Inline Wire. Widely used in solar panel, outdoor lamp and electrical wire connections. Cable connector type: Screw fixed- Internal 3 Cable Connector.
eBay
IP68 5pin Y-Type Waterproof Connector 6-16mm Cable Quick Screw Terminal Block 3-Way Wire Connector For Electrical Wiring DIY GO
Aliexpress UK