Rear hatch (lift hatch) LED light project

[Bob98SR5]

Gents,

To cut to the chase:

12v constant- tapped the white harness plug's thicker blue wire (rear window harness plug)
Switched ground- tapped the grey harness plug's Red/blue (rear wiper harness plug)

Note: I own a 98 4Runner SR5 w/ power rear window wipers and window.

I've been wanting to do this project for eons. Finally got around to starting mine after adding LED light strips to my wife's Ford Focus EV's pathetic trunk lights.

Hardest part for me was identifying which wires to tap. I'm the absolute worst at understanding the Toyota electrical manual (I really need to put some effort into it), so I bought a test light and started poking around.

Well turns out I was just poking around the Door relay harness only and was driving myself nuts. Well there is one constant 12v, but no switched. So long story short I finally wised up and got some common sense. Instead of poking the wires, I removed the harness plugs from the harness and poked the terminal pin ends looking for the elusive pin/wire that would ground when the hatch is closed.

And on that note, you can close the hatch without actually closing the hatch itself. Take a large flatblade screwdriver, push upwards on the mechanism. It'll only go so far, so you'll have to use your fingers to push the mechanism up the rest of the way and then use the screwdriver to push the latching mechanism all the way until it locks. If you have your rear cargo light set to "DOOR", it'll turn off the light.

To unlock, just squeeze the rear hatch handle as usual.

So basically I probed all the terminal pins on the male side of the harness plug until I found the ones that lit up the test probe. I noted which ones on paper. Then I faux-locked the hatch (method above) and probed again until I found the ground switched wire and the 12v constant. As for the ground switched wire, you'll know when you find it under the following condition:

1) Hatch lock is closed
2) Stock rear hatch light is set to DOOR
3) Positive wire from load (new LED light) is secured to the 12v constant wire

Procedure:

Remove the grey harness plug (the rear wiper) and probe the pins until you hit the switched ground terminal pin, which will then turn on the Stock rear hatch light as the test probe is applying a little bit of positive voltage to the pin. This creates a ground condition to that pin and thereby will turn on your the stock hatch light. Tap this same wire as your switched ground wire on your new LED light.

Now to select an LED light. I like the output of Mike's hatch light, but looking for something more rectangular. Any suggestions?

[4x4mike]

I'm not sure about rectangle but for less round of a shape I'd look into led rock lights. There are kits on Amazon and the like that offer leds in a housing that can be mounted in the hatch plastic. As you've seen there isn't much room between the back of the plastic and the metal shield in the hatch. Mounting some like I've linked below is much easier than hogging out a hole in plastic.

https://www.amazon.com/LEDMIRCY-Rock...783765&sr=8-18

Or the high dollar option:
https://www.amazon.com/gp/product/B0...p_bw_cr_x__a_w

[Bob98SR5]

Mike,

Thanks for the feedback and options. Looking at the ones you posted, I can see why you chose the one you did. I'll go with that one as well.

Bob

[Seanz0rz]

Thanks for the details on wiring Bob! I won't be doing this to my 4Runner, but it will be helpful for others.

And thanks for the lighting recommendations Mike! I'll pick up a set or 5 for the Lexus.

[Bob98SR5]

Damn these things are bright.

I worked from home today so I got a head start on finishing this project when the part arrived at 5:30PM. I purchased what Mike4x4 did, the KC HiLites Cyclone 5W LED, part #1350. It was a nice surprise to see that the kit included a pig tail with insulated (clear) male/female connectors. However the distance from the power and switched ground wires was too far from the location of the LED light, so soldering in longer wires was in order. I used 18 gauge for both. Soldering was a pain because of the height of the hatch, so use a small step stool if you're not 6'4.

Also you'll have to think about how and where to mount. I used a 13/64" bit to center a hole for a 3/8" bolt and the same for the wires. I centered my light right in the middle horizontally and vertically. The wires come out at the edge of the light. They are bendable so I bent them 90 degrees so as to hide the wire beneath the light. So drill your holes accordingly if you'd like to hide the wires. I didn't use rubber grommets either given the panel is plastic, but time will tell if that was a wise decision or not. Anyways if the wires fray, it'll just mean more soldering in the future.

I did one more thing too. The hole is quite large for an interior mount, so I used washer on the top side and a lock washer on the bottom side. I also painted the nut and the top side washer black to match the black color of the light housing. In retrospect I should've mounted the bolt the other way and painted the bolt head. But oh well.

Very impressed with this LED light puck. File this one under "Must do" and "Shoulda done it eons ago".

[Bob98SR5]

I didn't wire my light with a switch, but I may in the future. But for now I'm sure I'll be happy with how it is without a switch.

[4x4mike]

I really like my KC light. Ken and I did our 3rd gen hatch lights about 10 years ago. A lot in the LED world has changed since them but they were and still are great lights with quality parts. At the time we built them there were few out of the box options that were high quality and not a bluish tint.

I could have built another for the 4th gen but wanted to keep it simple and clean. The KC light is brighter than my old Cree setup and a bit more durable. It's a perfect addition and after having one for so long it would be difficult to be without.

While I like the mounting option, construction and color I think they are too bright for rock lights, at least for my need. I suppose I could go with fewer but one in each corner will give out enough light that it would probably be instusive.

Great job Bob.

[Bob98SR5]

Yeah it was hard to tell from the Amazon pictures, but I was impressed by the sturdy design esp the plastic lens face. I use my 4Runner like you Mike (lotsa trips to Lowes, HD, etc), so that rear cargo area is beat to death. Thanks for the inspiration. Perhaps next time I won't wait 10 years to do something like this

[Bob98SR5]

I decided to wire in a switch because in the past while camping, sometimes I leave the hatch open to create some shade and sit underneath it. No sense in running the battery low so tonight I added a non-illuminated SPDT switch with an inline 5W fuse.

Note: I didn't realize I bought a DT switch, in case you're wondering I've attached a powerpoint drawing of how the whole thing is wired up.

EDIT: in the attached diagram, there are two purple circles marked with "S". Those are the soldering points.