• Wiring Splices 101

    With all the winter mod's going on, many of them wiring related, now is a good time to review a skill we all run into, splicing a wire. This sequence comes from Hot Rod magazine and shows the best method to make a splice that will be strong, uniform and easy to do.

    1) Besides two pieces of wire, you'll need a solderIng iron, solder, a heat-gun or a torch, and a piece of shrink-wrap. Holyfield says, "I use a 40-watt iron; it's hot enough for almost all connections. A decent rosin core solder is suggested-not acid core, as it may harm some electronics.
    2) Expose the copper conductor strands by stripping about 1 inch of insulation off the end of both wires to be mated. If the wires already have a terminal on the opposite end, slide the shrink-wrap onto the wire before stripping off the insulation.
    3) On each wire, split the exposed conductor strands apart to form two V-shaped legs. a brittle point in the wiring system. I will show the method we have used at RM Motorsports for years. It has produced robust wiring systems on the vehicles we build and maintain ." Although these photos specifically illustrate the complex but sanitary "spread strand s"-style splice, the basic soldering technique is applicable to any soldered wiring connection.
    4) "Hand-shake" the two conductors together: Rotate the "V" legs on one conductor about 90 degrees relative to the other conductor's V-legs, then push them together until the two opposing V-groove bases make contact.
    5) Twist or "rope-braid" each leg segment around the conductor and insulation.
    6) Pull the two wires apart just enough that the conductor strands now touch only each other, and not the two wires' outer Insulation.
    7) Pre-tinning the soldering Iron's tip cleans contaminates off and also promotes heat transfer to the item you are soldering. Angle the solder flow-direction toward the center of the splice and away from the insulation. This keeps the solder from wicking up under the insulation and embrittling the wire.
    8) Solder the two wires together: Heat the wires up with the soldering iron, then feed in the solder on the hot wiring strands. If the wires are lying on something, space them off so the solder can flow freely into the wire strands.
    9) Let the wiring cool. Slide the shrink-wrap over the splice.
    10) Apply even heat to the wrap so it shrinks uniformly to seal-off the exposed conductor
    11) The simple "twist-together" method is the traditional way of splicing two wires together. Holyfield says it's weaker and will eventually fail.
    12) The simple twist splice ends up much bulkier than the interlocking V-strand method. Quality electrical tape works in a pinch, but doesn't offer as much protection anĚd strength as shrink-tube.

    Everyone who's guilty of the quick twist and tape method, please stay after school.