In general, to crimp spark plug wires, follow these steps.
- First, strip the outer layer of the wire.
- Then, determine the terminal type; single crimp or double crimp.
- If it is a single crimp, fold back the conductor wire onto the silicone jacket and use the crimping tool to squeeze the wire and the terminal.
- When using a double crimp, don’t fold the conductor wire. Instead, crimp the conductor and silicone jacket separately.
- Finally, connect the wire terminal to the plug boot.
Now your custom-made sparkplug wires are ready for use.
Crimp-On Spark Plug Ends
Even though pre-terminated spark plug wire kit manufacturers claim these wires are universal, they are not. In truth, they are semi-universal. Sometimes, these wires might not have the necessary length and can be expensive.
Considering all of this, creating your own spark plug wires seems like an excellent idea.Â
How to Crimp Spark Plug Wires?
Creating your own spark plug for the engine might seem a difficult task. But it isn’t. If you follow this guide, you’ll realize that it is all about execution. Here are the steps for crimping spark plug wires.
Things You Need

First and foremost, gather the necessary tools. For this process, we are going to use several tools. So, here is a short explanation of the tools that will be needed.
Pro Crimp Tool: Highly useful for crimping wires and terminals
Wire Stripper: Excellent tool for stripping wires
Plug Boot: Connects the spark plug and the ignition coil.
Terminal: Electrical connector for conductor wire’s end.
Step 1 – Strip the Wire

First, strip the outer layer of the wire using the wire stripper. Keep the strip length at 0.75 – 1 inches. For a double crimp terminal, you’ll need a smaller length. However, the above-mentioned stripping range is more than enough for both types of terminals.
Step 2 – Determine the Terminal Type
Depending on the type of the terminal, you’ll have to do some modifications to the crimping method. Because of that, this step is vital.
Double Crimp Wire Terminal
Most traditional spark plug terminals come with only one crimp. A double crimp terminal has two different spots to tighten the connection of the wire. For instance, you can find two spots for a conductor wire and a silicone jacket. On the other hand, a single crimp has only one spot. So, inspect the wire terminal closely and decide the terminal type.
Keep in mind: If you have a double crimp terminal, skip steps 3 and 4. After completing step 2, jump to step 5.
Step 3 – Fold the Conductor Wire

If you have a single crimp terminal, fold back the conductor wire onto the silicone jacket.

Now, slip the wire into the terminal. Push the wire until it gets inside the terminal saddle. It will prevent the wire from slipping out.
Step 4 – Crimp the Wire (Single Crimp Terminal)

Get the pro crimp tool and squeeze the spark plug wire and the terminal. Next, check the connection one more time.
Step 5 – Connect the Plug Boot

Now, slide the spark plug terminal into the plug boot.

If needed, use some grease to make the sliding easier.

Tip: After connecting the wire to the terminal, check the wire for continuity. Use a multimeter for this. This is an excellent method to check the resistance level and do it before sliding the spark plug terminal into the plug boot. (1)
Step 6 – Crimp the Wire (Double Crimp Terminal)
You’ll have to crimp the conductor wire and terminal separately if you have a double crimp. So, follow these steps.

- First, slide the wire into the terminal.
- Then, use the crimping tool to tighten the silicone jacket and the terminal.
- Next, tighten the conductor wire and the terminal.
- Finally, follow the instructions given in step 5.
Keep in mind: Always crimp the silicone jacket first. The silicone jacket covers more area than the conductor wire. So, the connection on the silicone jacket is much stronger. (2)
How to Put Ends on Spark Plug Wires
It is crucial to complete the above task successfully. With that in mind, here are valuable tips on crimping spark plug wires.
- Before starting, read the labels and manufacturer warnings.
- There are three configurations to crimp spark plug wires; removable terminal nut, solid terminal, and threaded terminals stud. Choose a configuration depending on your need.
Wrapping Up
After following the above 6-step guide on how to crimp a spark plug wires properly, you can understand crimping a wire is easy as striping a wire. So, now you don’t need to spend money on pre-terminated plug wire kits. Whether you use a single crimp or double crimp, you’ll get the job done quite easily.
Take a look at some of our related articles below.
- How to test ignition coil with multimeter
- How to test spark plug with multimeter
- How to test spark plug wires without multimeter
References
(1) resistance level – https://www.thebalance.com/how-to-trade-based-on-support-and-resistance-levels-4043477
(2) silicone – https://www.britannica.com/science/silicone
Video References
Talking Hands Tools
MSD Performance Ignition
rob miller
BSK Garage