If you need to connect when repairing car wiring or installing additional equipment polycoreOrdinary twisting will lead to oxidation of the contact after 3-6 months. The problem is different hardness lived: single-core aluminum or copper do not provide a tight fit to flexible multiwire veins, which causes transitional resistanceHeat and the risk of short circuit. In 80% of cases of failure of the auto electric car is to blame just such a "economical" connection.

In this article - only proven methods that use professional autoelectrics: from soldering with rosin to sleeve squeezing, indicating the necessary tools and consumables. We will also discuss why. Wago Other spring terminals are not suitable for all cases, and we will show how to avoid typical errors when working with wires of different cross-sections.

Why you can’t just twist a multi-core and single-core wire

The main mistake of beginners is trying to connect wires of different types squirt. Even if the contact seems solid, after several heating/cooling cycles (for example, when running headlights or a heater), the connection will weaken. Reasons:

  • 🔹 Different elasticity of materials: single-core wire (especially aluminum) "spring" less than polycore, which is why the twist is loosened.
  • 🔹 Aluminum oxidation: if one of the wires is aluminum, an oxide film with high resistance is formed in the air.
  • 🔹 Microfragments in multicore wire: individual veins break when twisted, reducing the cross section and increasing heating.
  • 🔹 Vibrations in the car: even a high-quality twist is loosened from constant shaking.

According to statistics of car service providers, 65% of problems with wiring after handicraft repairs are associated with such connections. For example, fire-fuse or flickering LED lamps Often the result is poor contact between flexible and rigid wires.

⚠️ Attention.: Coiling of multi-core and single-core wire without soldering or crimping is prohibited PUE 2.1.21 (Rules of electrical installations). In an electric car, this is fraught not only with equipment failure, but also with fire.

5 ways to connect reliably: the pros and cons of each

The choice of method depends on wire-stuff (copper/aluminum), cross-section, load and tool-readiness. Below is a comparative table with an assessment of reliability and complexity:

Method Reliability (1-5) Difficulty Suitable for aluminum I need isolation. Tool.
Pike. 5 Medium Yeah (flush) Yes. Solding iron, roaning iron, soldering.
Clutching the shells 5 Simple. Yes. Yes. Krimper, shells.
Wago's Clembs 4 Very simple. No. No. —
Bolt connection 4 Simple. Yes. Yes. Bolt, nut, washers.
Welded violin 5 Difficult. Yes. Yes. Welding machine, graphite electrode

For automotive wiring optimal ration (if access to 220V is available) and shell-cuff (for field conditions). Clembs. Wago convenient, but do not withstand high currents (for example, to connect a winch or inverter).

📊 Which method of connecting wires do you use more often?
Pike.
Clutching the shells
Wago's Clembs
A taped vial.
Other

Step-by-step instruction: soldering of multi-core and single-core wire

Sales are the most reliable way, but they require care. Suitable for copper wires with a cross section up to 4 mm2. If one of the wires is aluminum, use it. flux F-64 (not rosin!)

  1. Cleanup.Remove insulation by 15-20 mm (for soldering you need more contact area than for twisting). For multi-core wire, twist the veins into a tight pigtail.
  2. Flooding:
    • Put flux on both wires.
    • Warm up with a soldering iron (power 40-60 W) and apply a thin layer of solder on each wire separately.
  3. Connection:
    • Fold the wires in parallel or twist (for mechanical strength).
    • Warm up the connection and add solder until it flows in all intervals.
  • Isolation.Use a heat shrink tube (preferably a double) or a 3-layer insulation.

    • A critical error. wire-heating. If the insulation has started to melt, let the wire cool and repeat the tindering with less heating. It is recommended to use for car wiring acidless (e.g., FKET) to avoid corrosion.

    Cleared the wires at 15-20 mm|

    Put flux on both wires.

    He warmed up and smacked each wire separately |

    Connected wires and propile joint without voids |

    Isolated with heat shrinkage or tape--

    ⚠️ Attention.Do not use active (acid) fluxes for automotive wiring! They destroy contacts in 1-2 years. A sign of acid flux is a sharp smell and traces of corrosion on the wires.

    Clutching with shells: fast and reliable without soldering

    Cracking is the best choice for field conditions (for example, when repairing on the track). Suitable for copper and aluminum wires, but requires liner:

    • 🔹 GM - copper shells (for copper wires).
    • 🔹 HA - Alumomedium (for the connection of copper with aluminum).
    • 🔹 GCI Isolated shells (do not require additional insulation)

    The crimping algorithm:

    1. Select the sleeve by section (see para. (see table below). For multi-core wire, take the sleeve to a smaller size (for example, for 2.5 mm2 - a sleeve of 1.5 mm2).
    2. Clear the wires to a length of sleeve + 2 mm.
    3. Insert the wires into the sleeve from different sides (for better contact).
    4. Squeeze the crimper in 2-3 places (for shells up to 20 mm long, one crimp in the center is enough).
    Cross-section of wire, mm2 Color of the GCI shell Marking on the shell Max. Current, A
    0.5–1.0 Grey 1 10
    1.5 Blue 1.5 16
    2.5 Orange 2.5 24
    4.0 Yellow 4 32

    Use for car wiring HSI-sealed They do not require additional insulation and protect against vibrations. If the sleeve is uninsulated, after crimping, put on a heat shrink tube with a glue layer.

    💡

    To clench aluminum wires use the crimper with trapezoidal It does not cut soft metal, unlike standard mites.

    Wago: when you can use and when you can not

    Clembs. Wago They are popular for their ease of installation, but in automotive electricians their use is limited:

    • ✅ It's good.:
      • For signal chains (sensors, buttons, cabin lighting).
      • For temporary compounds (diagnostics, testing).
      • For copper wires up to 2.5 mm2.
    • ❌ Not suitable.:
      • For circuits with current >10A (starter, generator, winch).
      • For aluminum wires (oxidized in the clamping).
      • For places with vibration (under the hood, on the frame).

    In the terminals. Wago series 221 (lever) can be connected multi-core and single-core wires, but only if the load does not exceed 6-8A. For large currents, use series 222 or 224 paste Alu-plus (for aluminum).

    ⚠️ Attention.Clems Wago paste Alu-plus can not be used for copper wires - paste accelerates the corrosion of copper. For copper, take terminals without paste (transparent or orange).
    How to distinguish a fake Wago from the original

    The original terminals have:

    1. Logo. Wago on the body (not a sticker!).

    2. Marking of series and rated current on the back side.

    3. A spring of stainless steel (for fakes - ordinary steel, rust).

    4. Polyamide body (not melting at 120°C)

    Bolt connection: cheap and angry

    If there is no soldering iron or crimper at hand, you can connect the wires using bolt, nuts and washers. The method is suitable for copper and aluminum wires, but requires careful insulation. Procedure:

    1. Clean the wires by 20-25 mm (length depends on the diameter of the bolt).
    2. Make the rings at the ends of the wires (for multi-core – first twist the veins).
    3. Put the bolt on this order:
      • Puck
      • One wire ring
      • Puck
      • The ring of the second wire.
      • Puck
      • nuke
  • Tighten the nut to the point, then check the connection for break.
  • Insulate with insulation or thermal shrinkage (at least 3 layers).

    • For car wiring, use bolts. M4 or M5 (depending on the length of the wires). This method is often used for mass-wire body-bodied battery-stick repair.

    💡

    Bolt connection is the only allowed method of docking aluminum and copper without special sleeves (possibly). PUE 2.1.21).

    Common Errors and How to Avoid Them

    Even experienced electricians make mistakes when connecting wires of different types. Here are the most common:

    • 🔸 Use of acid flux Corrosion of contacts in 1-2 years. Decision: acid-free flux FKET Or roast.
    • 🔸 Insufficient twisting length (<10 mm) - weakening of contact. Decision: twist 15 to 20 mm.
    • 🔸 Pliers' squeezing - Weak contact. Decision: Use a crimper with a six-sided profile.
    • 🔸 Lack of insulation on the bolt connection - Short circuit. Decision: 3 layers of insulation + shrinkage.
    • 🔸 Copper and aluminum compound without transition sleeve Electrochemical corrosion. Decision:- HA Or a washer bolt.

    To check the quality of the connection, pull the wires in opposite directions. If the contact is not broken, everything is fine. Also check the connection location eclipsing (indication of overheating) or oxidation (Green coating on copper, white on aluminum).

    FAQ: Frequent questions about wire connection

    Can a multi-core and single-core wire be connected with a twist if it is well insulated?

    Nope. Even with the tape, the twist will weaken over time due to different wire rigidity. Use for temporary repairs bolt-joint or wago (if current <10A).

    What flux to use for soldering aluminum and copper wire?

    For the connection of copper with aluminum is suitable only flux F-64 or its analogues (F-34A). Canifol will not work – it does not remove the oxide film from aluminum.

    Which cartridges to choose for squeezing wires with a cross section of 4 mm2?

    For copper wires, ML-4 casing (Cross) for the aluminium, GA-4For mixed (copper + aluminum) GAAM-4. All the shells should be isolated (marking) GCI).

    Why is the connection of multi-core and single-core wire warmed?

    Reasons:

    • Weak contact (bad twist, weak cleavage).
    • Oxidation (especially in aluminum).
    • Insufficient cross-section of the wire for load current.
    • No insulation (short circuit on the body).

    Decision: Disassemble the connection, clean the wires until shine, connect with soldering or sleeve, check the cross section by current-sheet.

    Can Wago terminals be used to connect a car amplifier?

    Nope. Clembs. Wago Not designed for currents >10A, and the amplifier consumes 20-50A. Use it. ration or shell-crush shrinkable.