I take no responsibility if you hurt yourself or your truck, this is a reference only!
After installing my step bars, I decided to wire up some running board lights that operate when the doors are open or unlocked (i.e. when the dome light is on). Thanks to Borderbrat for some reference material in this thread: http://www.tacomaworld.com/forum/tec...tml#post297835
There are numerous lighting options, but I chose some cheap Harbor Freight LEDs since I had a bunch of coupons and they are advertised as being waterproof. We'll see how they hold up, but regardless, this approach is a good reference for just about anything, just be sure to use a relay if you use anything other than low-current LEDs.
Before you begin, disconnect the battery. I wanted the lights to turn on and off with the dome light (i.e. whenever the doors are unlocked or opened), so the dome light wires are the obvious choice to tap. As previously mentioned, I chose a low-current LED solution, so I can directly power them off the stock power wire and ground wire...if you choose lamps or devices that draws higher current, be sure to use a relay!
According to the stock wiring diagrams (available elsewhere on TW) and the Haynes manual, the power wire is a constantly powered 7.5A fused and is white, while the ground wire acts as the control line and is blue. The easiest place to locate them is the driver's side pillar.
UPDATE: I inserted an inline 1A fuse to isolate the LEDs from the stock wiring. The 7.5A fuse for the dome light will not blow before the thin wires that come with the LEDs, the 1A fuse ensures that the LED's thinner wires can be safely isolated.
Here you can see the tapped white power wire and the blue control wire. Be sure to tuck the wires back into the conduit and zip ties for strain relief.
After running the wires down to the left kick panel, I ran a quick test to make sure I tapped the correct wires.
I chose to run the passenger side wire through the cab instead of underneath the truck in order to avoid the exhaust and road hazards. The connection will be made near the left kick panel where I plan to insert an override switch and a 1A fuse to specifically protect against the LEDs and wires...the dome light 7.5A fuse will not blow if the LEDs or wires short out, so I want to protect the truck in the event my added circuit has a problem.
I continued to run the wires underneath the door sill trim....
then underneath the seat... (note: I just cut a small slit with an Xacto knife and run the wire through the grommet. You can also see the black wire I previously ran for my bed lights). The grey wire is a quality double insulation bundle, so it protects enough against scraping/shorting without conduit.
Here is the completed driver side wiring. Be sure to properly connect the wires (solder is best) and protect them using plenty of heat shrink, conduit, and electrical tape.
I didn't want to drill mounting holes into the truck, so I opted to use strong double sided trim tape (the stuff that holds your emblems on the truck). Be certain to clean the areas well with alcohol to promote a strong connection. Also, you'll need to wrap the conduit with electrical tape or else the double sided tape won't hold sufficiently. Note: in this pic you can see the grey wire running down from the grommet as well as both the front and rear lights. The unnecessary loop in the wire is because I didn't measure well enough and had to mount the excess somewhere.
Next, the wire needs to be run from the driver's side to the passenger side. Here's a pic where it is run through a bracket and up out of the way of the steering and pedals. Be sure it is secured out of the way to prevent an accident.
The wire is secured to an existing line (likely Air Conditioning wires or something), tucked underneath the rug, and sent underneath the center console.
Here's the wire coming out the other side of the center console, passed over the right kick panel and under the door sill trim.
Pull the wire taut and secure it...
Then replace the rug and hide the wires...
I poked a hole in the rubber blank on the passenger side and ran the wire through it. I then secured it and waterproofed the hole with silicone (black RTV).
The passenger side lights are then wired and mounted the same as the driver's side.
Here they are in the dark...
Materials cost less than $30 and they work exactly as expected. They light up both the step bars and the ground quite nicely.
UPDATE: I wired up another string under the hitch to illuminate the ground under the bed. This is good for safety, provides improved visability when at the rear of the truck, and for tailgating.