Electrical wiring of a car

The electrical wiring in a car is a system of colour-coded wires called the loom. Where several wires run side by side they are bound together with insulating tape or plastic sleeving.

Several modern cars have separate thin wires embedded in flat plastic strips. These strips are very compact, and are used mainly for accessories and relaycontrols that require little power.

Wires and bundles of wires are clipped to the bodywork to keep them out of the way. Where they run through a hole, the sharp edges are lined with a rubber grommet.

Sometimes the loom is divided into sections joined by multi-pin plugs and sockets, so that it can be removed and refitted section by section.

Joins in individual wires are usually made with crimp connectors. The colour on the sleeve of a connector denotes the size of wire it will take.

The bared ends of each wire are pushed into opposite ends of the metal-lined plastic sleeve, and squeezed with crimping pliers. There are multiple sleeves or other special connectors where a wire branches off.

Wires are usually connected to components by plastic-covered terminalswhich push on to a blade on the unit called a spade terminal.

Nearly all types of terminals should be fitted to the wire with crimping pliers .

There are a few types such as the `Scotchlok' which are secured by clips.

For additional security, you can add solder to the wire.

Use a 25-65 watt iron for most work, and a 150-250 watt one for large cables, or an 8 oz (225 g) gas-heated iron.