The ballast resistor keeps the engine running by preventing the engine from receiving full amperage from the ignition once started . In order to get the vehicle started, the starter sends a higher amperage to the spark plugs when you turn the key in the ignition. The spark plugs need the initial jolt to fire up.
Is ballast resistor necessary?
So does your application require a ballast resistor? Quite simply, if your distributor has breaker points the answer is yes ; if not, the answer is no. See all 7 photos 2 Older points-style ignition system used a single resistor which reduced amperage to the coil resulting in extended life for the coil and points.
What are ballast resistors used for?
A ballast resistor is a device in your vehicle that limits the amount of current in an electric circuit . The ballast resistor is commonly found in older vehicles, because they did not have the benefit of circuit boards found in most of today’s vehicles.
How do I know if my coil needs a ballast resistor?
Ballast ignition systems were introduced in around 1970. To find out for sure, use a multimeter to check the voltage on the positive wire of the coil with the ignition on . You can test the resistance of the coil using a voltmeter and measure the Ohms (resistance) across the +’ve and –’ve terminals.
Why do ignition coils need ballast resistor?
The ballast resistor allows the ignition system to operate at a lower voltage until the engine starts . ... The ballast resistor then functions to regulate the voltage going to the ignition system to avoid additional wear on the system.
Can you bypass a ballast resistor?
The duty of the ballast resistor is to limit voltage to the ignition coil. ... A quick and easy way to diagnose ballast resistor failure is to bypass it by running a temporary jumper wire from the battery to the coil . If it starts and remains running, you’ve found the problem.
Do you need a resistor with a 12 volt coil?
If a 6 volt ignition system is converted to 12 volts and a Delco style 12 volt coil with an internal resistor is installed as part of the conversion, no external resistors are required . The 12 volt battery must be connected so the negative (-) battery terminal is connected to ground.
Is the ballast bad?
Take out your current bulbs and replace them with the new bulbs. If the bulbs fail to light up, then 9 out of 10 times the ballast is culprit. ... If the ballast is good, an analog multimeter has a needle that will sweep to the right across the measuring scale. If the ballast is bad, then the needle won’t move .
Does a ballast reduce voltage?
Once the arc is established, the ballast quickly reduces the voltage and regulates the electric current to produce a steady light output. ... Thus, some ballasts have a separate circuit that provides a low voltage to heat the lamp electrodes during lamp starting and typically during lamp operation (Hammer, 1995).
What causes a ballast resistor to fail?
The resistance through the ballast resistor varies with current flow which varies with engine rpm. This naturally causes the resistor to expand and contract from heat . That’s why they eventually fail.
How do you test a ballast resistor?
To test your ballast resistor you need an ohm meter or multimeter set to ohms . Remove the connectors from both sides of the resistor. The ohms should read between 1.8 and 5 ohms. You should be getting 9 volts to the positive side of the coil.
What’s the difference between a ballast and non ballast coil?
What is the difference between the two types of coils? Basically, a non-ballast coil is designed to produce full spark output with 12 volts on the input (+ terminal) . A ballast coil is designed to produce the same spark output, but with only 6 to 9 volts on the input.
Can you bypass a resistor?
you don’t have to remove the existing resistor wire to bypass it. You leave it in place and : a) attach a 14 or 16 gauge jumper wire with scotch-locks at either end of the pink ni-chrome wire under the dash.
Where does a ballast resistor go?
Note: Ballast resistors are usually located bolted to the firewall if your distributor and/or coil is at the rear of the engine. If your distributor is located near the front or side of the engine in the case of an inline-4 cylinder, then it’s probably right near the ignition coil or distributor.
How many volts should my coil have?
The electrical system in your vehicle works on 12 volts , so every component must be based on 12 volts, as well. There is a wire connected to the ignition coil (known as a “hot wire”) that carries the 12 volts into the coil itself.
What Ohm ignition coil should I use?
Most ignition coils should have a primary resistance falling somewhere between 0.4 and 2 ohms ; however, refer to your manufacturer’s specifications for the correct reading. If a reading of zero is displayed, that signifies that the ignition coil has shorted internally in the primary windings and needs to be replaced.
