How much resistance should a spark plug wire have?
12,000 ohms-per-foot
Simply attach or hold a meter probe on each end of the cable and read the total resistance on the meter. The Society of Automotive Engineers suggests the maximum resistance should be 12,000 ohms-per-foot.
Does resistance matter in spark plug wires?
The higher voltage of a coil on plug or distributor system can create enough voltage that a slightly higher resistance wire will not greatly affect spark strength, but the relatively lower output of a magneto means using a lower resistance wire is more important to ensure a hot spark from the spark plug.
What is the resistance of an ignition coil wire?
The primary resistance is measured with the probes on the positive and the negative terminals of the coil. This value will vary between coils, but a rule of thumb on MSD’s coils would be between . 03 – . 7 ohms.
How many ohms should a wire have?
Two or three ohms is still acceptable, but if one of your cables shows much higher readings than the others (of the same length), you should check that all conductors of that cable really make optimal contact with the terminals in each plug.
How many ohms of resistance should a coil have?
A “standard” coil will have an internal resistance close to 3 ohms on its primary windings. The coil for a ballast ignition system will have a primary winding resistance between 1 and 2 ohms. The external ballast resistor (or resistor wire) will provide an additional 1.5 ohms of resistance.
How can you tell if a spark plug wire is bad?
Signs and symptoms of bad spark plug wires
- Hard starting.
- Engine misfire.
- Engine hesitation.
- Engine surging.
- Engine rough idling.
- Reduced engine power.
- Check engine light.
How much resistance is too much in a wire?
Ideally, the resistance should be 2000 Ω, but due to the existence of a wire, the measured resistance is 2000.01693 Ω, it’s less than 10 parts per million higher, nearly undetectable.
How much resistance is considered a short?
In circuit analysis, a short circuit is defined as a connection between two nodes that forces them to be at the same voltage. In an ‘ideal’ short circuit, this means there is no resistance and thus no voltage drop across the connection. In real circuits, the result is a connection with almost no resistance.
Why do spark plug wires have such high resistance?
Spark plug wires have an outer insulation several times thicker than the conductor, made of a very flexible and heat-resistant material such as silicone or EPDM rubber. The thick insulation prevents arcing from the cable to an earthed engine component.
What are the signs of bad spark plug wires?
Signs of Bad Spark Plug Wires
- Visible Damage on the Spark Plug Wires. Spark plug wires may start to dry out over time, so look for cracks in the insulation.
- The Engine is Idling Rough.
- Engine Hesitation.
- Engine Misfiring.
What is the typical primary coil resistance specifications?
normal resistance values, ranges between 6,000 and 30,000 ohms. Dwell is the measurement of the time that: the primary ignition current is turned on, measured in degrees.