Install Steering Wheel with Radio Controls and Modifying Turn Signal

Here is a guide for 4th gens on what you need to convert your steering wheel from one with no headunit controls to one that has built-in headunit controls. My car didn’t have steering wheel radio controls since it was ordered with the base sound system. I wanted them. This is what I had to do.
Installation time approx. 3-4 hours
This is not easy and is only for those who are comfortable with tearing things into many pieces. I could not get a straight answer from anybody when doing research into this project, so I ended up doing it with minimal knowledge on the subject.

You will need:


  • 1 steering wheel with radio controls (I found a ’99 wheel)
  • 1 airbag for said steering wheel (re-used mine)
  • 1 SIR coil/airbag clockspring (alternatively, a column) which has wires that match the airbag AND has a separate connection for steering wheel radio controls – MUST BE COMPATIBLE WITH YOUR CARS ELECTRICAL CONNECTORS. If you simply use a column you should swap the lock cylinder from the old column to the new column. (I used an ’01 SIR coil)


  • Metric/standard socket set
  • Torx bits/allen wrenches
  • Flathead and phillips screwdrivers (two flatheads)
  • A sharp metal pick of some sort (the kind you use to de-pin electrical connections)
  • Snap-ring pliers
  • Steering wheel removal tool
  • Steering wheel lock plate removal tool
  • Muscles!!

You can install steering wheel radio controls into your car assuming you have the wheel with the controls, the matching airbag, and the matching column (say you find a parts car with an intact column, wheel, and airbag).
Your car has an airbag connector and the cars wiring harness should already have a connector for steering wheel radio controls. All you need to do is add that headunit control connector either by swapping the SIR coil or swapping a whole column. I couldn’t swap columns so I did it the harder way (SIR coil). Here are instructions on how to swap the SIR coil:

  1. Remove the airbag
    Pull the airbag fuse or disconnect the battery, and wait 10 minutes for the power to drain from the system. The airbag system can retain power for up to 10 minutes so this is a very important step! The airbag is held onto the steering wheel via two T-30 torx bolts on the back side of the wheel. You may have to turn the key to RUN and unlock the steering wheel to access the torx bolts. Loosen the bolts (you do not have to remove completely) and the airbag should easily come out. Pull the plastic safety retainer clip and then pull the yellow connector straight out of the airbag.
  2. Remove the steering wheel
    Make sure the wheel is dead-center and the column is locked before continuing!
    When the column is locked in the dead-center position, loosen the nut holding the wheel on but don’t remove it entirely. Follow the horn wires to the white plastic spring thing. Twist counter-clockwise and pull and it will come out. Use the steering wheel puller tool to remove the steering wheel. Remove the tool and the nut. Once removed, set it aside (you can attempt to break it in half with your muscles AFTER you install the new wheel). The SIR coil is now exposed. Notice that the little arrows on the front of the SIR coil are lined up with each other.
  3. Remove the knee panel (yes, that’s right)
    Now the steering wheel is out of the way and there’s more room to work. Use the phillips-head screwdriver and a 7mm socket to remove the knee panel from under the column. You can unclip the electrical connection to the hatch release button with your fingernail.
  4. Disconnect SIR coil electrical connector
    With the knee panel removed, you can now see the bottom of the column and where all the wires come out. The large yellow wire and yellow connector is what you need to disconnect. It has an orange safety retainer clip so disconnect that first. Once the yellow plug is disconnected, you’ll need to remove the yellow plastic part of the plug or you won’t be able to slide it through the column without major disassembly. If you inspect it you’ll find that if you insert something small like that pick that I mentioned earlier, or a small flathead screwdriver, you can slide the yellow outer shell off of the black connector. Do so.
  5. Remove column electrical wire protector
    There is a frosted clear plastic shield under the column protecting the wiring. You’ll have to remove it. Squeeze the tabs closest to the front of the car and pull it towards the front of the car. It should slide out (but not easily – this is where muscles come in).
  6. Pull SIR coil
    Push the SIR coil in and use the snap-ring pliers to pull the retainer ring. If you simply don’t have snap-ring pliers you will have to get creative, but REMEMBER YOU WILL HAVE TO RE-INSTALL THE RETAINER. Set it aside in a safe place where you won’t lose it! Once the retainer is removed you can pull the SIR coil out a bit and let it hang by the electrical wire. If you followed step 5 you should be able to work the electrical wire all the way through the column (you’ll have to go underneath the column and help guide the wire as it goes along) until it hits the turn signal cam or lock plate. If you are lucky you can remove the wire without removing the lock plate or turn signal cam.
  7. Remove steering wheel lock plate
    Use the lock-plate remover tool to compress the lock-plate into the column, then use whatever tools available to remove the retaining ring and the flimsy metal shield ring thing. Set those aside in a safe place where you won’t lose them. Remove the lock plate removal tool and pull the lock plate. A plastic plate thing with a tube should come out with the lock plate. Set both of those aside in a safe place as well.
  8. Loosen turn signal cam
    You’ll have to loosen the turn signal cam (the gear things that rotate when you use the turn signals). Unscrew the phillips-head screw holding the assembly to the turn signal stalk and set it aside in a safe place. Now use a torx bit or an allen wrench and remove the three torx screws holding the assembly in place. You may have to rotate the assembly to get at all three torx screws. Set them aside in a safe place. Use a phillips-head screwdriver to remove the Hazard light switch assembly from the outside, and set the pieces aside in a safe place (be careful with the spring!).
  9. Remove SIR coil
    Now that the turn signal cam is loose, you should be able to rotate it counter-clockwise and finish pulling the old SIR coil.
  10. Install new SIR coil wiring
    Grab your new SIR coil and remove the yellow plastic part of the airbag connector on the under-column side so you can thread it through the column. Rotate the turn signal cam counter-clockwise and lift it up if you have to to thread one of the wires through the column, and after you are finished with that, do the remaining one. You may have to adjust the column tilt to get the wires through. I found that angled almost as high as it would go worked good. Go underneath and pull on the wires to make sure there is not any extra slack in the column.
  11. Connect SIR coil wiring under column
    Plug in both of the wires you just painstakingly ran.
  12. Reinstall column electrical wire protector
    Remember how hard it was to remove the wire protector shield? It’s harder now. Reinstall it by sliding it back in place just like how you removed it. It is necessary because you don’t want any of the column wires rubbing on metal and shorting out.
  13. Reinstall turn signal cam
    Screw in the three torx bolts and reconnect the turn signal stalk. I had a problem with the turn signal stalk connector becoming disconnected so I had to use a screwdriver from the outside next to the turn signal stalk to push the connector into it’s clip while holding the connector from inside the column. It’s hard to explain so you’ll have to figure it out when you get to that point. It is important and this step does take quite a bit of time if you aren’t lucky. Reinstall the Hazard switch too.
  14. Reinstall lock plate
    Install is reverse of removal. It goes on one-way and the plastic piece has to go on with it!
  15. Install new SIR coil
    Install is reverse of removal. When you set it in place on the shaft, go underneath and tug on the wires to make sure there is no more slack. MAKE SURE THE ARROWS ARE LINED UP ON THE FACE OF THE SIR COIL!!:
    Center a clockspring with no centering window and a spring service lock by holding the clockspring with the back side up. Depress the service lock and turn the coil in the direction the arrow points until the coil stops. Then, turn the coil 2 1/2 times in the opposite direction. Engage the spring service lock at the locking tabs.
  16. Reinstall knee panel
    Install is reverse of removal. Make sure the top clips are in!
  17. Install new steering wheel
    Place the new steering wheel on (dead-center) and tighten down the nut. Insert the white spring thing back into the hole and push/turn clockwise to lock it in place (this is for your horn). Connect the steering wheel headunit control plug.
  18. Install airbag
    Installation is reverse of removal!
  19. Test/Rejoice/Facepalm
    Put the airbag fuse back in and/or reconnect the battery, and test out the controls. Mine worked but the light bulbs were dead. I will desolder the bulbs and replace them with LEDs in the future.


This may not be possible on 98 or earlier models. You need to check underneath the dashboard to see if your car has the appropriate electrical connector for the controls. If it does not, then you will have to run new electrical wires behind the dash.

The wheel without controls is lighter weight than the wheel with controls. I didn’t get a chance to weigh each but it feels noticeable. The wheel with controls feels sturdier and more balanced than the wheel without controls.

While I was in there I sanded/filed/cut down the little plastic bits which control the turn signal stalk “feel”. I took a long time and got it sanded smooth, then re-applied some grease. The turn signal stalk no longer feels like it will break but on the flip side it now feels worn out, probably like a $2 hooker. I later found that the best way to relieve the tension was to bend the spring assembly away from the plastic contact area, therefore reducing the pressure on the plastic and reducing the amount of effort it takes to turn the stalk.

You can buy a brand new turn signal cam assembly in the HELP! parts section of your local Autozone/Pep Boys/Kragen/etc. if yours is broken or you filed it down like an idiot (read: me).

The SIR coil is also called an “airbag clockspring” but not according to GM, who will always refer to it as an SIR coil.


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And now for the extra stuff that I don’t recommend doing…

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