Turn signal switches have gotten complicated over the years. What once was simply a lever to activate the turn signals has added other functions: headlight dimmer, lights flashing, and even the horn button. Other stalks have also sprouted from the steering column, including wiper control and cruise control. Each addition has made changing the turn signal switch just a little trickier.
When the turn signal switch fails, it will probably be hard to use at first. It might seem to be loose, or stop returning when you complete a turn. The turn signals may stop working, or the headlight dimming function will become intermittent.
When the turn signals stop working, you need to troubleshoot before you start replacing expensive parts. If the switch is flopping around in your hand, it needs to be replaced, but other problems may originate elsewhere in the system.
- ½ inch drive breaker bar
- Marking pen
- Safety glasses
- Screwdrivers, Phillips and flat head
- Socket wrench set: ½ inch drive and ¼ drive
- Steering wheel puller
- Torx bits
- Workshop manual
Part 1 of 3: Removing the steering wheel
Step 1: Disconnect the battery. If your radio has an anti-theft security code, make sure you know what it is before proceeding. Put on your safety glasses, then loosen the battery ground cable clamp (usually a 10-13 mm nut) and disconnect the cable.
This is necessary to prevent setting an airbag code when you remove the steering wheel.
Step 2: Remove the driver’s side airbag. Most cars have torx fasteners holding the airbag to the steering wheel that are accessed from the side of the steering wheel that faces the dashboard.
Usually you can just unscrew these fasteners, pull off the airbag insert, and disconnect a small electrical connector at the back of the airbag.
- Warning: Airbags can be dangerous! Be sure to consult your workshop manual for the proper airbag removal procedure. Some models require that you do a deactivation sequence of some kind, while others are no more complicated than removing a horn button. Whatever it is, be sure to follow all the safety instructions for removing and handling the airbag.
Step 3: Remove the steering wheel. Remove the nut or bolt in the center of the steering wheel. Set the steering wheel straight ahead. Mark the steering wheel and the shaft with a marking pen so you can reinstall the wheel exactly as it came off. Then try to wiggle it off.
Sometimes a few raps with the heel of the hand are sufficient. Other times you will have to install a steering wheel puller to produce enough force to get it off.
When it does come loose, carefully pull it off the shaft while watching for any electrical connection that must pass through the steering wheel.
Step 4: Remove the steering column trim. How much of the trim has to be removed varies from car to car, but the lower half of the steering column trim almost always has to come out.
Removing the steering wheel may have exposed some screws, or all the screws might be accessed from the bottom of the column. Keep track of the screws and the positions they were in.
Step 5: Remove the clockspring. The next part you encounter will be the clockspring. It is a plastic housing covered with warning labels.
It contains a ribbon of wire that is wound up like a loose spring that enables the steering wheel to turn full lock right and left and still maintain a hard connection to the airbag controller.
The clockspring may be screwed down to the steering column or it may just snap in. It will be keyed to the steering column so that it turns with the column. The electrical connector to the car is usually under the center of the column. All the connectors in the airbag electrical harness are yellow or orange to make it easy to distinguish them from other systems in the car.
Disconnect the harness connector and pull the clockspring straight off. Set it somewhere where it will not be disturbed. You don’t want the center of the clockspring to turn at all while it is off the steering column. Some cars have a hole in the clockspring for the insertion of a pin to keep it from moving while it is off the car.
Part 2 of 3: Replacing the turn signal switch
Step 1: Remove the turn signal switch. The turn signal switch may be held on by a few screws or a pinch bolt around the column.
It might be a massive multi-function switch assembly, or the different switches may be discrete little boxes that come off separately.
The column switch might disconnect right at the back, or there may be a wiring harness that extends down the column. Look at the back of the switch to see what the arrangement is. There should be enough slack that you can pull it back some and leave it hanging.
Step 2: Disconnect the harness. Sometimes the harness connector will be located within the steering wheel trim. On some cars, you may find that the harness goes all the way down the column into the dashboard. If that is the case, you will need to take off the lower cover panels under the dash to access the connectors.
At this point the harness may just drop out of the bottom of the column, or you might need to pull it out and draw it through an opening. Pay close attention to the location of the harness and how well it is secured. Many cars with tilting steering columns allow the wires a certain amount of movement and you don’t want them to get caught on anything.
Step 3: Install the new switch. Fit the switch back into the column and reinstall the screws. Install any other switches that you might have had to take off as well.
- Note:If there were hidden fasteners on the steering wheel trim, be sure to reinstall the trim before going any further.
Part 3 of 3: Reinstalling the steering wheel
Step 1: Reinstall the clockspring. The clockspring should not have been disturbed while you had it off, so you can simply slide it straight down on the shaft, making sure that the flats on the shaft properly engage the center of the part.
- Note: If you had a pin in the clockspring, make sure to take it out.
Step 2: Reinstall the steering wheel. Line up the match marks that you made on the steering wheel and shaft and fit the steering wheel back onto the splines, threading the airbag wire through the appropriate holes at the same time. Install the bolt and tighten it with a torque wrench.
- Note: The workshop manual should have the factory specification.
Step 3: Install the airbag. Reinstall the airbag the way it came off, making sure to connect the small two wire terminal at the back.
If there was a deactivation procedure, reactivate the airbag by reversing the procedure according to the workshop manual.
Step 4: Test the turn signal switch. Start the car and try all the switches: turn signals, headlight dimmer, wipers, and horn. Take the car for a test drive and check the cruise control.
Make note of whether there is an airbag warning light on the dashboard. If you disconnected the battery before you began work, and did not reconnect it until the airbag was plugged in, there should not be a problem. An airbag code will come up if at any point you had the key on while the airbag was disconnected and can only be reset with the appropriate scan tool.
The turn signal switch can be a handful, because everything in the steering column is packed very close together. Plus there is the added complication of dealing with the airbag system. If you’re worried about working with the airbag or the clockspring, or getting the steering wheel misaligned, YourMechanic can send a technician to your home or office to service your turn signal switch.