Jeep TJ Airbag Switch Replacement Plate by iowncalculus

Last crawled date: 3 years, 4 months ago

Disclaimer:
This involves modifying a safety system on your vehicle. Perform at your own risk.
This is a switch plate that fits in place of the passenger airbag disable switch found in the center console on early (1997-2002) Jeep Wrangler TJs. Late TJs do not have this switch at all and have a different center console design. I designed this to fit a single rocker switch, though there's certainly room for more. The indicator light is a 0.312 incandescent from BGMicro.
In my case, the contacts of the passenger airbag switch were corroded and worn, so even though the switch was always left in the "airbag on" position, the "off" light would blink randomly going down the road. The switch is electrically very simple with only four pins. Pins 1 and 2 are connected to the "off" indicator light, and the Jeep computer expects to see some resistance there to confirm the light works. The other two pins (3 and 6) are connected to one of two resistors, depending on the switch position. The computer expects 175-190 ohms for passenger airbag enabled, 820-870 ohms disabled. With a worn switch like mine, the resistance would spike due to vibration and cause the computer to think the switch was off.
Because my TJ has a back seat, and I will never be placing anyone too small for an airbag in the front passenger seat, I elected to hardwire this in the "airbag enabled" position. I gutted the original switch for the connector and the 175-190 ohm resistor, which I soldered across pins 3 and 6. A small incandescent panel mount light (BGMicro LIT1059) is connected to pins 1 and 2, using some short wire extensions and some 2.8mm spade connectors. This light will satisfy the computer's requirements, and should only light up during the startup test. If it ever lights up any other time, something is wrong.
The rectangular hole fits any common Carling-style switch. Wiring this is left to the reader.
This plate is meant to snap in fairly firmly, like the original. I'm not completely satisfied with the tabs on the rear of the plate but they work well enough for installing it once. Given the print orientation I would not expect those tabs to survive a removal.
Unless you live somewhere that it never gets hot, you'll want to print this in PETG or a material with similar thermal properties. My PLA prototype deformed massively in the span of a few days in the Arizona summer.