You may have noticed that every brand or even model has a distinctive clicking sound when the turn signals are engaged. This rhythmic noise is synchronized with the activation of the light bulbs.
If you’ve noticed that one of your turn signals is now clicking significantly faster, it indicates a problem with a light bulb or the towing power plug.
The clicking noise behind the wheel isn’t just there as a reminder – it’s an ingenious system that allows the lights to run on and off in set intervals.
The original system was invented in the 1930s and has been used until the 21st century. Once you engage the turn signal switch, the current flows into a bimetallic spring. Heat is generated from the current and causes the spring to bend and touch another piece of metal.
This establishes a flow of electricity towards the blinker lights and they turn on. However, because the current is now flowing, the bimetallic spring rapidly cools and returns to its original shape, breaking off the connection. The cycle repeats and causes the lights to blink on and off.
Modern vehicles swapped this technology for an electromagnet, but the main operating principle remains the same.
The dashboard indicator for the turn signal is also powered by the bimetallic spring or the electromagnet, so aside from the clicking sound, the dashboard indicator will blink more quickly as will the turn signal lights.
The most common cause is a broken light bulb and it can be the front, rear, or a side/mirror mounted bulb. The system depends on the right of electric consumers to run optimally, but once a lightbulb stops working, the resistance of the circuit changes and disrupts the operations.
The other cause is rarely mentioned but I’ve experienced it numerous times when my towing gear was attached. Modern towing equipment is detachable, meaning that you need to install the hitch and the electric power socket for the trailer.
To adjust for the increased load of the extra turn signal lights on the trailer, the vehicle increases the voltage. With the trailer not connected but the power jack installed, some vehicles will produce faster blinking. Simply remove the power jack to solve this problem.
The way you’ll change a faulty turn signal light bulb depends primarily on the vehicle you’re driving. Accessibility is the most important and separates a 10-minute job from a 1-hour job.
Familiarize yourself with the process by watching a Youtube guide for your vehicle. Older vehicles had an abundance of space under the hood, but more modern vehicles pack everything so tightly that you’ll likely have to remove a few intake hoses or pull the headlight forward to reach the bulb.
Inspect the old light bulb for damage – discolored, charred or bloated glass, or broken filament wires inside the bulb. Because replacement bulbs are so cheap, if you’ve opened up the headlight you should swap it regardless of whether the old bulb looks damaged or not.
If none of the turn signals are working, even when the hazard button is pressed, that is indicative of a fuse or relay problem.
You’ll find the fusebox underneath the steering wheel, covered by a plastic shroud, or within the engine bay. Fuse layout is different for every vehicle, so consult the owner’s manual to find the turn signal fuse, or manually inspect them from top to bottom.
Fuses have a flat piece of metal going through the middle. If the casing of the fuse is discolored or the metal strip is broken, that fuse has to be repaired. Another way of checking the fuses is to use a multimeter or a test lamp and see if the current is flowing through the fuse while it’s still connected.
Relays should be positioned in the same box as the fuses, so find the one governing turn signals and test it with a multimeter to see if it’s still good. Between the two, you’re highly likely to find the cause of the problems.
In case one side of the turn signals is operating normally while the other doesn’t respond, the steering-mounted multifunction switch has most likely failed.
If the switch can be replaced without taking off the steering wheel, then you can do it yourself. The first step is to disconnect the battery, and then you’ll remove the plastic shroud surrounding the back of the steering wheel. From there, it’s a matter of disconnecting power plugs and unscrewing a few bolts to get the switch group off.
Some switches require you to remove the steering wheel completely, a task that is both difficult and dangerous because of the airbag. I wouldn’t recommend that you try this, and even I had taken my car to a mechanic for repairs rather than risk getting injured.
You most likely have the towing power plug installed but not connected to a trailer. You might have also missed checking the side blinker. Other than that, you should inspect the fuses and relays, as they’re the only reasonable cause left.
When you’re facing flasher relay or fuse problems, a clear sign is the complete lack of turn signal and hazard functionality.
These are very cheap, and you can replace them before troubleshooting. If it’s not the cause, you can keep the old one as a backup.
Turn signal bulbs go for $5 at most, and if you want to buy an LED version, they’re $15-25 for a pair. You’ll need one hex, Torx or a Phillips head screwdriver and around 10-20 minutes per headlight to replace the bulb. Tail lights are more accessible and can be swapped in less than 10 minutes.
You shouldn’t drive your vehicle for too long if the turn signals are flashing rapidly. The system was not designed to handle such a high cycle frequency and it can lead to bulb or control switch damage.
By far the most common cause is a bad light bulb as either the front, rear or side/mirror mounted bulb can disrupt the operation. This is not the case with the headlights or taillights, which can operate normally when one of the bulbs has failed. Still, you should always address these problems as soon as possible to avoid causing an accident.
The lifespan of a turn signal bulb has more to do with the car than with the bulb itself. Voltage inconsistencies, use, and some luck play a factor in how long a bulb should last. The figure of 4,000 hours is often thrown around, but you can also go by the estimate set by the bulb’s manufacturer.
Hazard and turn signal lights are governed by different fuses. Should turn signals stop working, check the fuse box and look for the failed fuse, as replacing it will solve the problem.
Yes, turn signals have a fuse and a relay. Failure of either one could cause a malfunction of the blinkers and hyper flashing.
Every vehicle has a differently organized fuse box, so the best way to find the turn signal fuse is to read the diagram located on the fuse box lid or read the owner’s manual.
Hyper flashing of the turn signals is neither safe nor legal so you should get it fixed as soon as possible. Luckily, the task of repairing it is very simple as you’ll either have to swap a bulb or change a fuse. VehicleFreak is dedicated to creating informative and useful guides for all drivers, so if you ever need advice on a repair, check out our website again!
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