What are HT leads, what do they do and why are they important in my car?
HT leads, or High tension leads, high tension cables or ignition leads, connect the ignition coil, distributor and spark plug. They need to be high quality, and capable of withstanding high temperatures.
The ignition coil first transfers the electrical spark energy to the distributor cap, which via the spinning rotor arm, travels down to the HT leads to the spark plug. Traditionally, ignition leads would have been made of a copper core tightly wrapped with a cotton braid, however modern performance HT leads are more likely to be made of silicone with a carbon core.
Our HT leads have a carbon ferroflex core, connected to a brass terminal via a conductive brass spike. This makes for a strong, flexible and durable lead. Many of our HT lead sets are available to buy off the shelf, however we also custom make HT lead sets for a wide range of automotive applications. If your car uses electronic ignition, you’ll need modern HT leads as copper leads will break down the ignition module, causing it to fail. Your HT leads are classed as a consumable, however our modern HT leads have a very long life cycle. Always check your HT leads as part of your general maintenance checks.