Harley Davidson Turn Signal Troubleshooting

Welcome to the world of Harley Davidson. In this article, I am going to focus on a very specific troubleshooting, and that is Harley Davidson turn signal troubleshooting.

Harley Davidson Turn Signal Troubleshooting

Harley Davidson Turn Signal Troubleshooting

When Turn Lights Flash Too Slow or Too Fast:

This issue with the turn signal is not quite ordinary. But there is a possibility of this occurring once in a while.

The indications: If you find this issue after you have replaced the flasher or any of the bulbs, this indicates that you might have installed a different flasher bulb which is not meant for your bike model.

If any of the light bulbs seem to be burned out, this can make the indicators blink faster than usual.

Some other possible problems that can cause a change in flashing rate-

  • The lamps having a poor power connection might be a potential issue.
  • If the connection at the turn switch is loose, this will lead the indicators flash at a different rate.
  • Sometimes, overcharging your battery can also cause this issue. Make sure you charge your battery appropriately and check on the blinking of lights as frequently as possible.
  • On the contrary to the previous point, an undercharged battery might lead the light blink at a slower rate. Check if your alternator if it is undercharging the battery.

When Turn Signal Lights Do Not Work:

This one is a pretty common problem faced by many. Sometimes, none of the turn signal lights does work. Usually, a blown fuse, a poor flasher unit, or a faulty turn signal switch may be the reason behind this problem. You can check the light bulb sockets and/or the power to detect any further issues.

Some other consequent issues with this-

  • Bulbs in poor condition.
  • Inspect the bulbs’ outlook and structure.
  • The ground connection not working properly.
  • You might find an open or short.

When Turn Signals Do Not Flash:

Sometimes, it is seen that the emergency bulbs light up, but they do not flash or flicker. You can check for a burned-out bulb at first since it is one of the usual reasons behind the issue. If you find this to be working just fine, a lousy flasher unit or a bad turn signal switch might be the cause. Check for this to detect the issue.

As a complementary, check if there is any blown circuit fuse. To do that-

  • Ensure that the circuit connections are in proper condition, not loose, corroded, or unplugged.
  • Check the wiring or terminals for the rear part of the circuit. Look out for a bad connection between turn signal switch and circuit the flasher, and/or between flasher and ignition switch.
  • Take a look if there is any bad contact or open circuit between the power side connection with the turn signal switch.
  • At last, don’t forget to check for an open or short in the lamp’s circuit.

When Turn Indicators Do Not Work While Turn Signals Do:

This issue indicates that the indicator lights do not illuminate, but from the outside, they work fine. The possible reasons behind this can be-

  • Corroded or damaged sockets
  • Blown indicator bulbs
  • A bad ground
  • Any trouble regarding the flasher unit

You can use your user manual as your guide and get access to the bulb and repair panel, and ground connection for more information. You will find that; some models use two different lights for left and right turns. Some others use one light for both of the indicators.

If you see that the instrument panel uses one light for both directions, look for any faulty mechanism in the flasher unit. Sometimes, the brake light, taillight, and signal light, one light bulb expresses all.

When you replace a lamp, ensure that you have installed the bulb properly.

You need to check the indicator light bulbs and the flasher unit in case you find out that the turn signal lamps from the outside work but the indicator lights do not.

Test Your Turn Signal Flasher

A foolproof method of testing flasher units is to use a familiar and decent unit. Since that is not always feasible, you can test the circuit connection in the flasher when it is installed on your bike. We recommend to keep the repair manual close to your hands and follow it when you need to.

Before you get started, keep in mind that this procedure is suited for analog type flasher units. If your bike has a solid-state unit, you need to follow the repair manual for special instruction. You need to use a digital multimeter with 10 or more mega-ohm of impedance. It will help you to save the intricate circuits in your bike while you are in the process of troubleshooting.

To start with the procedure-

  • Firstly, you need to identify the location of the flasher. For your convenience, look for it under the dashboard. Near the steering column, the battery, or at the “power center”. Your repair manual comes in very handy in this case.
  • Then, find out the wiring diagram for the lamps.
  • Match the colors of wires that connect with the flasher unit. Figure out the wire which provides power to the flasher. Then, find out the wire that goes from the flasher to the turn signal switch to operate the lamps of the turn signal.
  • Now, connect the test light with the ground.
  • Now you have to switch on the ignition, however, do not start your engine yet.
  • Try operating the turn signal in the left or right direction.
  • Take the wire connecting to the flasher unit and back probe it. You will find the test light to illuminate. But if you do not find the light to illuminate, you might have a blown fuse or an open between the flasher and fuse box/battery.
  • Back probe the wire again, but make sure you do not operate the turn signal switch. Now, if the test light does not flash, it is alright. If it flashes, that is an indicator of the flasher turning bad.
  • Now, follow the same process but this time, it is with switching the turn signal on. And similar to the previous one, it should yield the opposite result- meaning, the flashing test light indicates the good flasher and vice versa.

When Your Turn Lights Do Not Go Off

This particular problem is a different kind of turn signal failure as it is linked to the mechanical error of the signal switch instead of the electrical system. The most common cases are like- you turn on the signal for the left while in traffic, but after you have stalled at the side, it still goes on flickering even if you have turned the signal off.

Generally, two reasons are observed behind this issue. One, the canceling finger that is inside the switch is broken. Two, the canceling cam or clock spring is broken. If it is the first issue, the switch needs to be replaced. For the latter one, you need to reassemble/replace the cam or assembly. This might vary depending on the particular model.

Most of the causes of these failures are resolvable without much expert supervision. Nonetheless, keeping the repair manual at hand might come useful, as you may need to check them from time to time.

For any sort of advanced repairing, if you are not sure what to do precisely, contact a professional repair worker to deal with the sensitive details. Sometimes, a new problem is created while treating the old one with unprofessional hands.


Frequently Asked Questions (FAQs)

My left signal turns on if I push the button for the right. Why does it happen? Often, it does not work at all.

  • It is an indicator of a fault in a multi-function switch. Test it thoroughly or seek professional service.

Why does not my turn signals come on?

  • It may be because of a failure in the flasher signal.

Sometimes, switching the left signal on turns the front, right, and back signal on intermittently. Why does that happen?

  • It sounds like it is a problem regarding loose wire. It happens quite sometimes. You can detect the source of the issue using a test light and wiring diagram, which is available in the repair manual of your bike.

What might be the reason for indicators not going off while the hazard lights work fine?

  • The bulbs might have been blown out. Check for them if they are in good condition.

My turn signal does not work, but the flashers work fine. What might be the problem?

  • The turn signal switch might be faulty to cause this issue. A test light to check that part of the circuit can be helpful. You can find the details in the manual.

Sometimes, my turn signal does not work at all. But if I press the hazard switch, it works just fine. Why is that?

  • If it is a multi-function switch, this might be a reason for this issue. You can try nudging the hazard switch; this helps sometimes. But for a permanent, stable solution, try replacing it as soon as possible. Make sure you shop for the new switch carefully. Test it out before purchase if necessary.

My turn signal works fine when parked. But while driving, it flickers once or twice. Why is that?

  • Circuit relay maybe the problem. Check for it if it is failing. If not, the switch might e the problem.

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Abdulla Zatar
About Abdulla Zatar

Hi, I’m Abdulla! Your go-to tech troubleshooter! Sharing my knowledge so that you can fix your tech issues with ease. Let’s make fixing things easy and fun!

1 thought on “Harley Davidson Turn Signal Troubleshooting”

  1. I have a 2009 ultra classic and the rear turn light is dim on one side with the running lights are just on everything else works fine. I even the switched the wire for the other light and it was the same way on that light.


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