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.
Do I need a resistor for my coil?
And while ignition coil life may be compromised without a resistor, the additional secondary voltage (at the spark plug) is increased which generally improves power. 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.
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.
Why do some 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.
Do you need a resistor with electronic ignition?
Electronic ignition systems, whether factory Mopar or aftermarket, don’t utilize breaker points, thereby not actually needing a ballast resistor to control amperage through the pickup coil.
How many ohms should a 12 volt coil have?
You should have a resistance reading of at least 3-4.5 ohms . A bad coil will show a higher reading then 3-4.5. Next, place the red or black lead from the meter to the centre of the coil , and to either one of the terminals positive or negative. You want 9500-10000 Ohms, a little less is ok but no more.
How do you check the resistance of a coil?
- Set the multimeter to measure resistance (ohms).
- Connect the positive lead to the positive terminal of the coil.
- Connect the negative lead to the negative terminal.
- A typical value would read 0.4 – 2 ohms.
What happens if you don’t use a ballast resistor?
If the ballast resistor is not working properly, the vehicle will not start . Since it is an electrical system, it is something best left to the professionals to handle. The only way to have the vehicle up and running again is with a ballast resistor replacement.
How many volts should my coil have?
The average vehicle ignition coil puts out 20,000 to 30,000 volts , and coils used in racing applications are capable of 50,000 or more volts at a constant rate. This new voltage is then routed to the distributor via the coil wire, which is just like the spark plug wires, only normally much shorter.
Why does a 12 volt coil need a resistor?
What is an external resistor on an ignition coil? The external resistor coils were used to boost primary ignition voltage during starting (making starting faster/easier). During starting, the external resistor is bypassed; once the starter is disengaged, power to the coil flows through the external resistor.
What does a ignition resistor do?
Due to its application, such devices are called Ignition Ballast Resistor. Use of this device reduces the risk of coil failure . It is installed in the circuit between the primary voltage source for the ignition coil and the coil stud. ... This jumper wire provides the necessary voltage to make the engine start.
Why do leds need a resistor?
An LED (Light Emitting Diode) emits light when an electric current passes through it. ... The ballast resistor is used to limit the current through the LED and to prevent excess current that can burn out the LED . If the voltage source is equal to the voltage drop of the LED, no resistor is required.
How can you tell if a 12 volt coil is bad?
To check your coil, ensure you have 12V going to the positive terminal . Once you confirm that is the case pull the wire out of the centre of the distributor and hold it a cm away from the distributor centre terminal. Have someone crank over the engine, and there should be a nice blue spark..
Should negative side of coil have power?
The power from the ignition switch need to go to the plus side of the coil and the negative goes the the distributor on a 12v system. That should be opposite what it was on a 6v positive ground.
Can you test a coil with a multimeter?
If you suspect the coil is dead, you can also remove the coil, plug it back in, and use an ignition spark tester like OEM 25069 to determine if the coil is firing. You can also use a multimeter to test resistance.
