High-tension leads are responsible for transferring electrical current from the battery to the ignition system. Fault in the high-tension leads can disrupt the electrical flow to the engine, thus making the car immobile. Fitting a high-tension cable is an easy task that only requires a pair of pliers. However, it is important to know which type of high-tension lead is more suitable for your car. Read on to find out how to fit new high-tension leads in the car for better ignition performance.
Signs of Faults in High-tension Leads
High-tension leads are designed to withstand extreme conditions. Even though they are made with durable material with very low resistance, the leads begin to deteriorate with time due to constant wear and tear. Some of the signs that indicate a fault in the high-tension leads are mentioned below:
- Difficulty starting the car
- Misfiring of the car’s engine
- Reduction in the engine’s power
- Sudden surging or idling of the engine
- Hesitation in the engine
- The appearance of the check engine light
Types of High-tension Leads
Primarily there are two types of high-tension leads available in the market:
- Carbon core high-tension lead
- Copper core high-tension lead
Carbon core high-tension lead
As the name suggests, the high-tension lead is made from carbon core. The benefit of carbon core is that it completely blocks out any radio interference. Another plus point of a carbon core lead is that it comes with already installed connector terminals and dust seals. The leads are easily pushed in the distributor and the coil without additional adjustments. However, the carbon core leads are very susceptible to damage since they cannot withstand any kinks as the carbon core can snap easily.
Copper core high-tension lead
The copper core high-tension lead is sturdy and stiff since it is made from copper metal. But unlike the carbon core leads, these leads require manual tweaking. You have to cut the insulation on the lead and need to attach screw-on connectors by yourself. These leads come in different shapes like the crimped-on terminal with a dust seal, the screw-on terminal with a collar, and the crimped-on terminal with a collar. The copper core high-tension leads also cause a lot of radio interference, so you need to get leads with in-line suppressors and resistive plug caps to overcome the disruption.
You can choose the type of high-tension lead according to your preference and utility.
How to Fit New High-tension Leads
Fitting a carbon core high-tension lead is fairly simple since they already have the terminals crimped-on at their ends. You need to remove the older high-tension leads from the coil and distributor and fit the new high-tension leads in them. However, if you opt for copper core high-tension leads, you will need to follow some additional steps of screwing on the connectors or terminals before you can fit the new leads into the ignition system.
Removing the Old High-tension Leads
Before knowing how to fit new high-tension leads, it is important for you to know how to remove the old leads first. Follow the following steps to remove the old high-tension leads from the ignition system:
Step 1 – You have to start by disconnecting your car’s battery to avoid getting shocked.
Step 2 – Now, you have to remove the plug caps from the distributor cap.
Step 3 – Undo the knurled thimbles that hold the leads in place. Some leads are screwed in at the distributor; you have to check if there are any leads screwed in.
Step 4 – Using a screwdriver of an appropriate size, unscrew the screws holding the leads in place. Since the distributor cap is made of plastic, make sure that you do not end up damaging the distributor cap with the screwdriver.
Step 5 – You can now pull the old leads out of the car.
Fitting the New High-tension Leads
Take the old leads along when purchasing new ones so that you are able to get the length of the leads right. Follow the steps mentioned below to fit new leads in a car’s ignition system:
For Carbon Core High-tension Leads:
Step 1 – Clean the sockets of the distributor cap from the inside with an emery cloth.
Step 2 – Push the dust seals back on the leads.
Step 3 – Now, attach the leads to the coil and the distributor cap by simply pushing them in.
Step 4 – Put the dust seals back and fix them in place properly. Make sure there are no loose connections; otherwise, the engine will experience issues when the car starts.
For Copper Core High-tension Leads:
Step 1 – Using an emery cloth, clean the distributor cap and its sockets thoroughly.
Step 2 – You have to use a sharp knife to cut off about an inch of the insulation on the new lead. Make sure you don’t damage the copper core while cutting through the insulation.
Step 3 – Now, you have to push a crimp-on terminal on the exposed core and flatten its extensions with a plier.
Note: You don’t have to cut through the insulation for a screw-on terminal. Just insert the connector into the lead and tighten the screw so that the core gets pierced.
Step 4 – Connect the leads back to the distributor cap and coil.
Step 5 – Tighten the leads in place. Depending on the design of the distributor cap, you have to either screw the leads in or have to tighten them at the knurled thimble. For better results, you can also change the spark plugs at this point.
Step 6 – Put the plug caps in place and reattach the distributor cap to the distributor.
Step 7 – Reconnect the battery.
Before reconnecting the battery, check if it has the right amps by testing the battery. Charge the battery with a battery charger for a certain time if required. If the battery is completely depleted, you should get a new battery immediately. Also, check the battery’s leads and connections for any damages.
There you go, easy steps to replace your high-tension leads. Turn the ignition for testing; if the car still has trouble starting up, other reasons might be involved. Use a multimeter to find electrical defects in the system. Also, check and replace any fuses if they are blown.
Knowing how to fit new high-tension leads in a car is important since the high-tension leads are very prone to damage. A timely replacement can save you the unnecessary hassle of ignition failure, which can be time-consuming and costly.
