Flasher Buyer’s Guide
- The car flasher, is a small, usually cylindrical component that’s often located in your vehicle’s fuse box. The flasher is used to turn on a car’s turn signals or hazard lights, and can be mechanically or electronically operated.
- There are two main types of flashers available today: thermal flashers and solid state flashers. While both have the same function, they have some operational differences.
- An LED flasher relay, or more accurately, an LED-compatible flasher relay, must be electronically operated because LED lights don’t produce enough current to heat and initiate the operation of the turn signal lights.
- On average, car flashers can cost anywhere from around $10 to $100. The flashers on the more expensive end of the price range are usually heavy-duty flashers, while the cheapest ones are usually thermal flashers for older vehicle models.
Automotive lighting is one of the most important elements of any type of vehicle. All the different interior and exterior lighting, even the lights on your dashboard and other electronic modules, all have their own specific and important functions. Not only that, they also make your vehicle look amazing.
While headlights and taillights get the most attention, there are other exterior lights in your vehicle that are also crucial to your safety. These include the turn signal lights or hazard lights. To ensure that your turn signal lights and hazard lights work reliably in any situation, a small but important component called the flasher or car flasher is required.
What Is a Car Flasher?
The car flasher or flasher is a small, usually cylindrical component that is often located in your vehicle’s fuse box. The flasher is used to turn on your car’s turn signals or hazard lights, and it can be mechanically or electronically operated.
How Does a Flasher Work?
The flasher is triggered when you push the turn signal lever or rod up or down. The flasher connects to the turn signal switch, which then turns the blinkers or turn signal lights on. On a standard mechanical flasher, operating the turn signal or hazard light switch or lever sends current to flow through the flasher to the turn signal lights. This current isn’t enough to turn the lights on, but it creates resistance, which causes a spring steel to heat up and expand. This allows the spring steel to make contact and actually switch on the turn signal or hazard lights. The spring then cools down and causes the light to turn back off. This all happens very quickly and continuously as long as the switch or rod stays in place, which results in the regular blinking you see on the turn signal lights.
In modern flasher modules and LED flashers, this process is typically controlled electronically, so there’s no spring steel that needs to be heated up to activate the blinking lights. Instead, electronic flashers are relays that are operated by a circuit with a transistor and with help from a timing chip.
Types of Car Flashers
There are two main types of flashers available today: thermal flashers and solid state flashers. While both have the same function, they have some operational differences.
A thermal flasher is practically synonymous to the mechanical flasher described above. As the name suggests, they work through thermal expansion and contact of the spring steel. This type of flasher is common in vintage vehicles. Thermal flashers are able to create the blinking operation and clicking sound of turn signal lights mechanically.
Solid State Flasher
A solid state flasher is the most common type of flasher used in modern vehicles. This type of flasher is electronically operated. Solid state flashers or electronic flashers are typically used for trucks with multiple flashing lights or LED turn signal lights. These types of flashers are able to mimic the blinking operation produced by old thermal flashers. On top of that, they’re also designed to mimic the clicking sound that goes with the blinking of the turn signal or hazard lights.
LED Flasher Information
With modern vehicles shifting towards the use of LEDs in most automotive light applications, including turn signal lights, the issue with old thermal flashers became apparent. Because LEDs produce very little current, they won’t be able to heat up the bi-metal strip that activates the turn signal lights. This means that an LED flasher relay, or more accurately, an LED-compatible flasher relay, must be electronically operated.
However, it’s important to know that not all electronically operated flasher relays can work with LED turn signal lights. If you need an LED flasher module for your LED turn signal lights, you need a flasher with a ground wire to establish working connections between the flasher and the LED turn signal lamp assemblies.
Identifying a Bad Flasher Relay
The symptoms of a bad flasher relay are easy to spot. If your turn signal lights or hazard lights aren’t working or are working intermittently, your flasher might be bad. The problem is ensuring that the flasher is the component at fault and not the switch, the lights themselves, or any other part of the turn signal light system. You’ll have to test the component to know whether or not the flasher module needs to be replaced.
Testing a flasher will depend on the type of flasher you have. For thermal relays, you can use a circuit tester to see if it’s working. A thermal relay usually makes a clicking sound to show that it’s still operational. For electronic or transistorized relays, isolating flasher problems is more difficult. You might have to check and isolate all components to determine that your flasher is the one at fault.
How to Choose the Right Flasher for Your Vehicle
When shopping around for a replacement flasher, compatibility is the most important thing that you’ll need to consider. An OE-replacement flasher, whether aftermarket or OEM, will help you ensure that the flasher you’re getting is designed to simply replace and work the same way as the existing flasher relay. However, if you’re replacing or have replaced your original halogen turn signal lights with LED ones, you can’t go wrong with a direct-fit, OE-style replacement flasher.
If you have an LED turn signal light assembly, you need to choose a solid state flasher that’s compatible with your specific vehicle.
How Much Does a Flasher Cost?
Flashers are hardy components. They’re meant to last for a very long time. The good news is that even if your vehicle’s flasher fails, or if you’ve switched to LED turn signal lamp assemblies and need to update your flasher module, you don’t have to spend a lot on the component itself. On average, car flashers can cost anywhere from around $10 to $100. The flashers on the more expensive end of the price range are usually heavy-duty flashers, while the cheapest ones are usually thermal flashers for older vehicle models. Before you purchase a flasher, make sure that you’re buying one that’s compatible with your specific vehicle model and the type of lights that you have.