Does ballast need resistor
Christopher Lucas
Published Mar 24, 2026
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.
How much resistance should a ballast 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.
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.
What does a ballast resistor do on a coil?
A Ballast Resistor is an electrical device that reduces voltage to the coil so that more energy is available for the spark plugs during starting.How do I test a ballast with a multimeter?
To measure it, set your digital multimeter to around a thousand ohms resistance setting. Connect the black leads to the white ground wire on your ballast. Afterward, test every other wire with the red lead. When you do this test, a good ballast will return an “open-loop” or max resistance.
Do I need a ballast resistor with MSD ignition?
Late-model electronic ignitions or an MSD Ignition do not require the ballast. If you are looking to upgrade your stock coil, or want to compliment the performance of your MSD Blaster Ignition, MSD 5, 6, or 7, the Blaster Coil line is the right choice. Our Blaster Coils are designed for improved spark output!
What will a bad ballast resistor do?
If your ballast resistor is bad, your vehicle will not run and you will have to have it towed to the mechanic’s shop. … The biggest sign your ballast resistor is bad is your vehicle will start, but immediately stop as soon as you let go of the key.
Does a ballast resistor have polarity?
Resistors are not like diodes or capacitors. They do not have a polarity. The conduct (or resist) current equally in both directions of current flow. In manufacturing, you will often see resistors all installed in the same direction.Do I need a ballast resistor with Pertronix and MSD coil?
Pertronix setups still need a resistor unless you run there coil (which probably has one built in already) Its just you have to wire the pertronix box to have a full 12 volts so you cant run it off the resistor wire feeding the other brand of coil.
What is an external resistor on an ignition coil?The <old style> 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.
Article first time published onHow do I know if the ballast is bad?
- Flickering. …
- Buzzing. …
- Delayed start. …
- Low output. …
- Inconsistent lighting levels. …
- Switch to an electronic ballast, keep lamp. …
- Switch to an electronic ballast, switch to a T8 fluorescent.
How do you check if a ballast is bad?
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. If you’re using a digital multimeter, often the digital readout will possibly list a “1” when it doesn’t find a measurable resistance.
What is the voltage output of a ballast?
Fluorescent lamps use a ballast which transforms line voltage to a voltage to start up and operate the lamp(s). Newer fluorescent ballasts are usually rated for both 120 volts and 277 volts. Some are rated for only 120 volts, others for only 277 volts (used in commercial environments).
What is the difference between a ballast and non ballast coil?
A ballast coil is designed to produce the same spark output, but with only 6 to 9 volts on the input. With a non-ballast coil, the input to the coil is the same, 12 volts, whether the engine is running, or being cranked by the starter motor.
How do you connect a coil to a resistor?
Strip the end of the positive wire from the ignition, and connect it to the positive end of the resistor. From the other terminal on the resistor a wire goes to the positive on the coil. Make sure to attach securely to the connecting terminal, by wrapping the wire around the post and tightening with a screwdriver.
Does a MSD Blaster 2 coil need a ballast resistor?
blaster two Yes, you must have a ballast resistor. I kept the stock bosch one but in retrospect I would use the MSD one that came with the coil next time.
Which PerTronix coil do I need?
The 3.0-ohm coil should be used on PerTronix Ignitors installed on four- and six-cylinder engines while 1.5-ohm coils should be used for eight-cylinder applications. These coils can be used on virtually any inductive (non-capacitive discharge) ignition system.
How does the PerTronix ignitor work?
“The points operate mechanically with a rubbing block that rubs on a small cam in the distributor. This rubbing block wears, which changes the timing and the point gap, altering both the performance and the amount of spark available,” Don explains.
How do you test a PerTronix flamethrower coil?
Attach an 18 or 20 AWG jumper wire from the negative coil terminal to an engine ground. Attach positive (red) lead of your voltmeter to the positive side of the coil, and the negative (black) lead to an engine ground. Turn the ignition switch to the run position. Now read the voltage at the positive coil terminal.
Why are my fluorescent lights flickering?
If your fluorescent bulbs flicker, most likely the problem is with the bulb itself. If the bulb is very dark on either end, it may be defective and burned out. The best way to test the functionality of a bulb is to put it into a fixture you know works. … Flickering fluorescent lights can also be a result of temperature.
Can you fix a ballast?
While simply swapping burned out bulbs in an existing ballast is deemed “ballast repair” by many – and can offer advantages in longevity and energy savings – sometimes this simple “fix” is not enough.
Why do my fluorescent lights not turn on?
The fluorescent tube won’t turn on No electrical power due to a tripped breaker or blown fuse. A dead or dying ballast. A dead starter. A dead bulb.
Can you hook up a ballast resistor backwards?
Resistors lack polarity. There is no backwards.
What happens if you put a resistor in backwards?
Resistors are blind to the polarity in a circuit. Thus, you don’t have to worry about installing them backwards. Current can pass equally through a resistor in either direction. … The resistance value is typically written next to the resistor symbol.
Is there a right way to install a resistor?
no, any direction will work.
Will a bad ballast burn out bulbs?
The ballast itself can go bad, which causes lights to flicker or even appear to be burnt out, when in fact they aren’t. They require maintenance and energy to power, on top of the power used to light the fluorescent bulb. They are a large part of the equation when using fluorescent lamps.
How long do ballasts last?
According to the Certified Ballast Manufacturers Association, the average magnetic ballast lasts about 75,000 hours, or 12 to 15 years with normal use. The optimum economic life of a fluorescent lighting system with magnetic ballasts is usually about 15 years.
Can a bad ballast cause a fire?
As with any electrical situation where overheating is possible, a bad ballast can pose a fire danger. The overheated ballast could cause the plastic housing on the light itself to melt and, in the right conditions, flame up.
How do you bypass a ballast?
- Step 1: Disconnect All Power So There is No Electrical Current. …
- Step 2: Find the Ballast. …
- Step 3: Locate and Cut Only the Hot and Neutral Wires. …
- Step 4: Cut the Socket Lead Wires. …
- Step 5: Remove the Ballast (if you wish) …
- Step 6: Connect the Wires. …
- Step 7: Reattach Any Coverings and Turn On.
Why wont my fluorescent bulbs work?
A dead fluorescent can be caused by lack of electrical power (tripped breaker or blown fuse), a dead or dying ballast, a dead starter or a dead bulb(s). Check for power first… then the starter (if applicable) and then the bulbs. When all else fails, the ballast should be replaced.
Do all fluorescent lights have ballast?
All fluorescent bulbs require a ballast. All compact fluorescent (CFL) bulbs require a ballast, which is often integrated. All HID bulbs require a ballast, which is sometimes integrated. No LED bulbs require a ballast, although some are engineered to work with an existing ballast.