Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How Long Does a Ballast Resistor Last?

How Long Does a Ballast Resistor Last?

ballasts resistor

A ballast resistor is a component in the ignition system of older vehicles. If you drive a classic, you are familiar with coils and points. You don’t have an onboard computer, and obviously you don’t have circuit boards that can control the voltage when you start up your engine. This is where the ballast resistor comes in. It is actually something like a huge fuse that is located between the positive battery cable and the ignition switch, and it works to lower the voltage that is delivered to the coil so that it doesn’t burn out. When you crank your engine, the ballast resistor ensures that the normal battery voltage is delivered to the coil in order to start the engine.

If the original ballast resistor is still working in your classic car, then you are a very lucky driver. Because the ballast resistor takes so much heat during normal operation, it is vulnerable to damage and will eventually wear out. How often you drive could be a factor, but there is no specific “best before” date. The ballast resistor could last for many years, but it does take a lot of wear and tear, and it could fail suddenly. Your ballast receiver needs to be replaced if the engine cranks but stalls as soon as key is returned to the “run” position

If your ballast resistor fails, you will have to have it replaced. Resist the temptation to listen to well-meaning classic car fellows, who may suggest jumping the resistor. If you do, your points will ultimately burn out, and you will require expensive repairs. A professional mechanic can replace the ballast resistor and have your beloved classic running properly again.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...

Related questions

Q: After hour or so driving, engine starts to sputter as if not receiving fuel. Stop for 10 mins and it runs fine.

The stalling could be due to a heat induced failure of the ignition coil. Resistance of electrical components increases with temperature and if the coil is the issue that is why the stalling only occurs once the engine is hot....

Q: When I turn my headlights on my windshield wipers come on and they don't stop. Also the right side headlight get very dim.

Check the ballast resistor for the headlights and see if it has a burned wire or loose connection. If not, then the ballast resistor needs replaced for the headlights. A ballast resistor will balance the power to the headlights ensuring...

Q: No heat, no sound, no nothing

Hi. An electrical diagnostic by a certified professional would determine if the blower motor, resistor, relay, wiring, and switch are operational. It is not unusual for the resistor block to go bad and certainly that can be looked at first....