You can call it whatever you want… but that’s a Tacoma with underglow!
Haha I had to- it actually looks great.
Finch said:
You can call it whatever you want… but that’s a Tacoma with underglow!
Haha I had to- it actually looks great.
LOL I mean you’re not wrong… the underside is glowing!
I used a 5-pin SPDT relay to hook the lights to the entry lighting circuit, so they turn on whenever you unlock, approach, or open the door. The dimming function stays in place. They’re also wired to my switch panel for independent control with just a button press.
Big thanks to tcodyw88 on Instagram, and his video on YouTube, for the wiring help!
Images of rock light locations (I made custom brackets for the rock sliders)
Used 12 Harbor Freight ROADSHOCK LED Rock Lights ($162)
@Tate
The T-Tap to the switch panel powers the lights through the dome lights or just the switch panel? If you turn on the dome light to look at a map, will the rock lights come on?
TundraTitans4 said:
@Tate
The T-Tap to the switch panel powers the lights through the dome lights or just the switch panel? If you turn on the dome light to look at a map, will the rock lights come on?
There’s no t-tap to the switch panel.
The t-tap actually goes into the yellow wire (pin #11) from the a-pillar harness, which connects to #87a on the relay. This yellow wire is a switched ground for the dome light circuit, so the rock lights come on when you unlock, open the door, or approach.
The wire from the switch panel to #86 on the relay lets me control the rock lights separately.
Turning on the dome light with the headliner switch won’t turn on the rock lights though.
@Tate
Looks great! Don’t let people hate, these are really handy for packing/unpacking, finding things you dropped, or just for safety. Be careful with this wiring though. When the courtesy lights turn on, the extra lights pull current through the BCM. 4.4W x 12 lights / 12V = 4.4A. That’s a decent amount of power.
@Renny
Thanks man! Are you sure about that power draw? I’m not the electrical expert, but as far as I know, the power to the rock lights is coming directly from the battery with an inline fuse. They’re controlled by a switched ground to #30 on the relay. I’m not familiar with BCM, but the lights shouldn’t be drawing power from the dome circuit, just using it to trigger the relay.
@Tate
BCM = body control module. It controls stuff like lights and locks. The dome light circuit (except when you manually flip the ceiling switch) is controlled by the BCM. It gets the unlock/lock/door open signals and powers the lights. The dome lights get 12V all the time, and the BCM grounds them to turn them on.
The current runs from ground to the source, meaning it’s going through the whole circuit, not just the positive side.
Is 4.4A enough to cause trouble for the BCM? I’m not sure.
A safer option would be:
- 85 → diode → bed light circuit.
- 85 → rock light switch → chassis ground.
- 86 → fused 12V+.
- 87a → leave open.
- 87 → ground to chassis (not connected to 85).
- 30 → rock lights (-).
This setup avoids overloading the BCM and keeps the current clean. The downside is losing dimming for the rock lights.
You could use the bed light circuit since it activates with the dome circuit, but without the dimming effect. The diode keeps current from flowing backward into the bed lights when you turn on your rock light switch.
Disclaimer:
- I’m an engineer but not an electrical one.
- I’ve been looking into these circuits lately as I plan to do something similar.
@Renny
Wow, thanks for the detailed info! You clearly know your stuff.
I don’t want to rewire everything (and I like the dimming function), so I think I’ll keep it as is. I’ll be the test case and let you know if I have issues with the BCM. What do you think the extra 4.4A could do? Could it blow a fuse, or is it worse like frying the BCM?
@Tate
Yeah, the rock lights would stay connected to the battery positive, fused.
Could be a blown fuse, could be a fried BCM. It’s unlikely it would damage the truck too badly.
Renny said:
@Tate
Yeah, the rock lights would stay connected to the battery positive, fused.
Could be a blown fuse, could be a fried BCM. It’s unlikely it would damage the truck too badly.
Which wire would I tap for the bed light circuit?
So, would I connect two wires to #85? One to the bed light circuit (through the diode) and the other to the switch panel (+) terminal on the fuse block, and then to ground?
@Tate
Also, the way it’s wired now, only your rock light dash switch (pin 30) is triggering the relay. When the dash switch is off, the lights ground through 87a (through the BCM). When you turn the switch on, the relay closes and the lights ground through 87 instead.
Idk man… the lights are cool but they’re kinda corny too. This looks like it belongs on a lifted truck that never goes off-road.
Vincent said:
Idk man… the lights are cool but they’re kinda corny too. This looks like it belongs on a lifted truck that never goes off-road.
Cheers man, I get it! Everyone has their own taste.
@Tate
I don’t hate how it looks, and I bet it’s awesome off-road. Just feels a little too over the top for me, lol.
Vincent said:
@Tate
I don’t hate how it looks, and I bet it’s awesome off-road. Just feels a little too over the top for me, lol.
If these were rainbow RGB, I’d agree, but I think the solid white light and placement look clean.
I’m not driving 60 mph on the highway with these on, lol. The main use for these is off-roading at night, and the courtesy feature is helpful when getting in and out in dark parking lots.
That lock/unlock and approach feature is so cool.
Del said:
That lock/unlock and approach feature is so cool.
Thank you 
Now you can see the lines on the road instead of swerving everywhere and tailgating!