A lift truck’s ignition system varies depending upon the type of forklift it is. It all starts with a battery, though, which turns on the motor of an electric forklift or enables combustion in an internal-combustion engine. Another common part of the ignition system are the wires which connect all the other components with each other regardless of the type of lift truck.
In a gasoline-powered or propane-powered internal-combustion forklift, power from the battery flows to an ignition coil which is, basically, a small high-voltage transformer. The ignition switch (or starter), operated by a key, activates the electrical system by providing power to the ignition coil. The coil is connected to a capacitor which smooths the electrical output of the ignition coil and to the distributor cap. The electricity produced by the coil flows through distributor caps with rotors to a distributor which allocates the electricity to spark plugs that produce sparks to ignite the fuel and air mixture in the engine. A diesel-powered forklift truck does not use spark plugs because fuel is injected directly into the engine’s cylinder. It does, however, use glow plugs to pre-heat the chamber and facilitate combustion. Throughout the entire process, it is the wires that carry the electricity from one component to another.
Wires, those threads, strings or cables that carry electricity from one point to another are among the most under-rated forklift ignition parts. They are commonly cylindrical metal strings made of alloys of platinum, silver, iron, copper, aluminum and gold wrapped in an insulating material such as plastic, a rubber-like polymer or varnish. The right wire size is important because the size determines how much electricity the wire can carry. Following the American Wire Gauge system, the factor to consider in determining the right wire are wire gauge, wire capacity and what the wire will feed. The smaller the wire gauge, the more electricity it can handle before overheating and causing a fire. In forklifts, wires are usually bound together in a compact assembly known as a wiring harness that keeps loose wires from being scattered all over the vehicle, protects the wires from vibrations, sudden movements and moisture and saves on space as well.
Because forklift brands are designed differently, the wiring of a Toyota forklift may be different from that of a Caterpillar truck or a Hyster forklift even if the sequence of the wiring may be the same. Wiring a Yale truck, a Clark forklift or almost any other brand will consist of disconnecting the battery cables, removing the ignition assembly, replacing the wiring harness and reconnecting the battery cables. The main differences will lie in where the battery and the ignition assembly are located in the individual make and model of the lift truck.
Wires can be compared to the body’s nervous system because they deliver energy impulses to different parts of the truck as needed. In conducting maintenance work on forklift ignition parts, don’t neglect to check on the wires that keep the juice flowing.