How do I know if my ballast resistor is bad?

Symptoms of a Bad or Failing Ballast Resistor

1. Vehicle starts, then immediately dies. The most obvious symptoms will be the vehicle starts, but then immediately dies as soon as you release the key.
2. Not starting at all.
3. Don’t jump the resistor.
4. Let the vehicle be.

Can I bypass the 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.

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.

What is the purpose of a ballast resistor in an ignition system?

In simple terms, the ballast resistor in a Mopar limits the amperage, or current flow, through the coil while the engine is running, thereby extending the life of the coil and breaker points of the distributor.

How do you check a ballast on an ignition coil?

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.

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.

Does a ballast resistor have to be grounded?

A Ballast resistor should NEVER be grounded! The resistor limits the CURRENT going through the coil. Also, if you have a points ignition, it lengthens the life of the points greatly.

What is the purpose of a ballast resistor?

Does a ballast resistor reduce voltage?

The ballast resistor, supplies the needed voltage during the start up, and then immediately after the arc is established, it reduces the voltage in addition to regulating the current flow.

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).

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.

How do you test a ballast resistor?

Mopar Ballast Resistor Test. Using an electrical multi-meter, check the resistance between the noted terminals of the ballast resistors. Do this with all of the wires to the ballast resistor disconnected. Any significant deviation from these numbers would indicate that the ballast resistor is defective.

What does a ballast resistor do?

“Ballast” is something that gives stability and hence a resistor used for over current or over voltage protection in circuit that in turn gives stability to the circuit is referred to as ballast resistor. These ballast resistors have major applications in areas of automotive and in lamp circuits.

What is the purpose of an ignition ballast resistor?

Definition WordNet Search defines a ballast resistor, most commonly found in an automobile ignition system, as a device “inserted into a circuit to compensate for changes, [such] as those arising from temperature fluctuations.”. A ballast resistor helps regulate voltage flowing in an electrical system to avoid overloads or battery drainage.

What is a ballast resistor coil?

A Ballast Resistor is an extra electrical “load” which is installed in the electric circuit providing power to the ignition coil for the purpose of reducing the voltage that the coil receives. This may seem somewhat counter-intuitive as one would think that the higher the voltage to the coil,…