Toyota FJ Cruiser Forum banner

Not open for further replies.
1 - 1 of 1 Posts

103 Posts
Discussion Starter #1 (Edited by Moderator)
To read the original full thread and post questions/comments on this topic, please go to

Attached is a schematic of how the OEM AUX Switch should be wired up.
Last week I ordered a Switch and pigtail from TRDSource, and while I was waiting for the parts to arrive, I did some research on how to wire it all here on the forums. I came accross some VERY good threads, most notably

NCFJ's Not So Basic Wiring Diagram
WVFJ's Wiring Aftermarket Lights with Toyota FJ Cruiser Off Road Aux Switch

Alot of credit goes out to these guys for the clear and concise information they provided. I decided to throw together a schematic of how the OEM AUX switch should be wired, and print it so that when I install the wiring I would have a handy reference. Figured I would post it.

Here is another breakdown of the switch pins, keeping in mind that the pin layout is labeled while looking INTO the terminals, with the locking tabs on the right:

Pins 1 and 2 are the power and ground for the green LED built into the switch. When the switch is depressed, this little LED lights up and tells you that the switch in "ON". Basically a little indicator. 14-16 gauge wire is fine.

Pins 3 and 4 make up the switching circuit. You have a choice from where you would like your pin 3 supply to come from, and your decision will determine the opperational conditions of the lights. Again, 14-16 gauge wire.

  • If you wire pin 3 from the battery/fuse panel, you will be able to use the AUX lights ANYTIME, ignition on or off. Good choice if you want to illuminate something with the car off. However, if you forget about them being on and go to bed, your FJ's battery is going to be dead in the morning.
  • If you wire pin 3 from a switched 12V source, the AUX lights will only work when the ignition switch is in the "ON" position.
  • Additionally, you can wire pin 3 from any 12V supply wire on the vehicle, but be aware that the AUX lights will only operate when that specific supply wire is active.
Pin 4 is the output to the relay. On the relay, there will be a picture of a little internal coil and switch, and labels for which pins are which. Wire pin 4 of the AUX switch to one of the pins on the relay that connect to the internal coil circuit. The other pin on the relay of this coil circuit should be grounded.

Pins 5 and 6 serve as the gound and supply for the backlight of the switch, meaning that whenever your interior lights are on, you will see the switch lit up similar to the ATRAC switch. As an easy hook up, tap the wire coming from the AUX switch pin 5 to the white/greentrace wire coming out of the ATRAC switch. Then, tap AUX pin 6 to the green wire coming out of the ATRAC switch. 14-16 gauge, if needed, is fine.

A couple more notes, the KC lights and their respective wiring should be in the 8-12 gauge range, considering these lights are rated at 135W. Also, the optional fuse panel is a good idea if you want to keep all wiring seperate from the stock circuits. Tons of good threads about them, too.

Hope someone can use this stuff!
1 - 1 of 1 Posts
Not open for further replies.