Wiring up the airbag
I had the benefit of having the STi clockspring. This means I had an extra plug for the airbag that I could use. If you do not want to cut your plug, then you will need to order one. I don’t know the part number, so don’t ask.
Here is the back of the STi airbag as I had it. At a minimum you will need the plug coming out of the back of it.
Take the wires coming out of the plug on the back of the STi airbag and strip some of the insulation off of the end of them. Then you will need to get an airbag plug. If you want you can cut it off of your WRX airbag, or you can order one. Either way, you will need one. Strip some insulation off of the end of the wires coming out of the plug. I matches up the colors of the wires on my airbag wires to the plug, but if you re-use your WRX plug then you need to make sure that you hook It up right. This is how I figured to wire it. If you set the airbag so that the wires come out of the plug pointing down (or towards you if it is on a table), then the wire on the left gets hook to the left side of the plug, and the right one to the right side of the plug. I reference the plug by the green release thingy. Once you get the wires matched up properly, it is recommended to solder them together and then wrap them with heat shrink
. I did not have either at the time, so I butt-spliced them together and wrapped them in electrical tape.
After you wire the plug to the end of the wires on the airbag, you are ready to install it into your car. Take the steering wheel, making sure that the clock spring is lined up properly, and slide it over the spline. Take the nut and screw it back onto the spline and torque it to around 22 ft/lbs. Once the nut is torqued you can hook up the cruise control and plug in the airbag. Once the airbag is plugged in, you can plug in the horn. There isn’t much room inside the steering wheel, so you will need to tuck everything back in there. Line the airbag back up with the Torx bolts and tighten them down to hold the airbag.
Once the steering wheel is reinstalled, make sure no one is in front of the car and re-attach the battery. Once the battery is re-attached, and the airbag hopefully hasn’t come out, go to the passenger’s side door and place the key in the ignition. While you are doing this, be careful to keep your head clear in case either airbag deploys. Start your car, and if you did it right, everything should work.
I do not assume any liability or responsibility for any unwanted results that occur from doing this modification. Precautions must be taken because you are dealing with one of your car’s safety features, the SRS / Airbag. If you do not feel that you can safely do this modification, then don’t do it. Read ALL directions before even attempting to start this project.
Let me know if there are any questions,