Are distributor ignition coils
the same as ignition coils?
Distributor ignition coils and ignition coils are similar components, but not necessarily the same. Distributor ignition coils are ignition coils used in older vehicles with distributor-based ignition systems. Modern vehicles often use a different type of ignition system, such as a coil-plug system that does not use a distributor. However, some newer vehicles may still use distributor ignition coils. So, while distributor ignition coils
are a type of ignition coil, not all ignition coils are distributor ignition coils.
What is the function of distributor ignition coils?
The function of the distributor ignition coils
is to convert the low voltage from the battery to the high voltage needed to create a spark at the spark plug. This spark ignites the air/fuel mixture in the engine's combustion chamber, which powers the vehicle. In older vehicles with distributors, the distributor ignition coils fit inside the distributor and send high voltage to the correct spark plugs at the correct time. In newer vehicles with distributorless ignition systems, each cylinder has its own ignition coil.
How to test distributor ignition coils
Here are the steps to test the distributor ignition coils
Disconnect the ignition coil from the distributor and use a multimeter to measure the resistance between the primary terminal (where the distributor's wires connect) and the secondary terminal (where the high voltage wires connect to the spark plug). See your vehicle's service manual for the specific resistor value to look for, but generally speaking, a healthy coil has a primary side resistance of about 0.5 to 1.5 ohms and a secondary side resistance of about 5,000 to 15,000 ohms.
If the resistance value is not within the specified range, the coil may be faulty and should be replaced.
You can also perform an induction spark test to check for sparks. To do this, reconnect the ignition coil to the distributor and remove one of the spark plug wires. Plug a spark tester into one end of the wire and ground the other end of the tester to the engine block. Crank the engine and watch the tester for sparks. A healthy coil produces a strong spark.
If you don't see a spark or the spark is weak, the coil may be faulty and should be replaced.