What is a ballast resistor replacement?

In your car’s old-school “points type” ignition system, the ballast resistor serves as a bridge between the positive battery cable and the ignition coils.
This component controls how much juice flows from the battery to the ignition coils, preventing them from overheating and getting damaged.
Ballast resistors are cheap parts, typically only costing around $10 to $20. Labor costs can range anywhere from $50 to $250, depending on where you live.
Unfortunately, ballast resistors will go bad over time. They take a lot of abuse, constantly heating up and cooling down until they’re worn out entirely. You’ll need to get this part replaced eventually.

How to perform a ballast resistor replacement

Here’s what your mechanic will need to do while handling your ballast resistor replacement:
  • Use a multimeter to check the voltage entering and exiting the ballast resistor. If they match up, a ballast resistor replacement is necessary
  • Remove the battery and battery tray
  • Disconnect and remove the blown ballast resistor
  • Install and connect a new ballast resistor
  • Reinstall the battery tray and car battery
  • Use the multimeter to check the voltage again. This ensures the replacement resistor is working correctly
  • Take the car for a test drive to make sure everything is working correctly

Do I need a ballast resistor replacement?

If your ballast resistor has failed, it’s unlikely your car will even start. When you turn the key over to the START position, the engine will fire up, but as soon as you let go and the key settles into the ON position, the engine will die abruptly.
If this describes your situation, you most likely need a ballast resistor replacement.
Another indicator would be the need to replace ignition coils. If an ignition coil is damaged and needs to be replaced, always make sure the ballast resistor is checked too.

How important is a ballast resistor replacement?

If your car needs a ballast resistor replacement, the engine probably won’t turn over properly. Your ballast resistor could possibly be failing while still operational, though—which would lead to bigger problems.
If you manage to detect the need for a ballast resistor replacement before the part itself fails, make sure you get it fixed immediately to avoid potential damage to the ignition coil and other vital engine components.

How to find cheap car insurance

We just explained how a ballast resistor prevents too much voltage from reaching your ignition coil. Similarly, the Jerry app prevents too much money from exiting your wallet when paying for car insurance.
Jerry is a powerful shopping tool that makes it easier than ever to switch insurance and save. You’ll browse up to 50 quotes from top insurance companies tailored to your needs. The average Jerry user saves $887 a year on car insurance!
Jerry can find you not only great car insurance, but homeowners and renters insurance too. And you can sign up for your new policy without making any calls or filling out stacks of paperwork. Jerry does all of that for you!
“Jerry really just saved me $954 on my new car insurance payment. I’m feeling great!” —Irene M.