Wiring LED Truck Bed Lights to Factory Switch

LINK to Manufacturer install Video:
https://youtu.be/fbpmmI20uiA
1. Mount your lights. These are two strips of four.
2. Run wiring into cab. Do this by finding a route from the truck bed to under the driver's side of your taco. There are holes, you just need to find them underneath your trim pieces.
3. Combine the power wires between the lights. Combine the grounds or negative wires between the lights
4. Install add a circuit and connect power wire.
5. Remove harness from factory switch, and tap your combined ground wires to the blue wire in the harness as shown below.
6. Reassemble your trim pieces, and enjoy.
Cargo Light Tap: I ran the power wires from the lights to my fuse box with an add a circuit, then tapped the cargo light wire that connects to the factory switch.


Photo Credit: @caribe makaira <--- This guy is a genius. . .follow him! @caribe makaira
Power Tap (+) from the LEDs to the fuse box:

Factory Switch Tap: (Note: some people will say that you should use a relay, but i didn't need one for these little lights)
Blue Tap is me combining the grounds (-) on the two strips of LEDs, and the red tap is me tapping the (-) from the lights to the factory switch.


My personal video of lights in action: https://youtu.be/Q5ovtfsR680

You may have noticed a light bar on the back. Install video here: https://youtu.be/B3sKxN6Dv88

 

Your attached photos don't work.

// edit - Make sure your new lights don't draw too much current, because now that current is going through the wire powering the original light, and that wire was not intended to power that light and two additional ones. It may blow a fuse, or (worst case), fry the wire and start a fire. This is unlikely, but something you still want to be careful with.

The reason people suggested using a relay is to avoid the potential problem above. You'd still tap the same wire, but it would only be used to turn the relay on/off, and there would be little to no additional current draw on it. You would have to run a separate power wire (from your battery, preferably through a fuse/box) for your two lights, though.

 

What he said.

 

If I were to add a relay to my current set up, how would I wire it?

 

Updated OP

 

Use a

$13 ESUPPORT Car Relay 12V 40A SPDT 5Pin Switch Socket Plug Wire Harness Automotive Pack of 5

standard automotive relay. It'll have four or five terminals labeled #30, #85, #86, #87 #87a.

Run a wire with an inline fuse from the battery to terminal #30 (power input). Run an identical wire - same thickness - from terminal 87 (power output) to your new lights' positive connection. Run the lights' negative connection to a ground.
Terminal #85 will be your switch to turn the relay on. This can come from the tap you already put on the original light's power.
Terminal #86 will be a ground.
If your relay has a #87a, leave it empty.

When you use the original switch to turn on the rear light, that light's positive connection (the one you tapped) will get powered, and your tap will result in the relay turning on, allowing input power from terminal #30 to exit via terminal #87, thereby powering your new lights.

 

See below, am I getting what you're saying? (I don't want to have to go through the firewall if I don't have to)

 

@Corneeeeelius - yes, proposed config diagram is correct, but drawing main power from an existing circuit w/ the add-a-fuse defeats the purpose of the relay. You want to have an entirely separate circuit, powered straight from the battery.

Using a fuse tap from the factory fuse box still results in a situation where more current is being drawn from that original circuit than it was intended for. This isn't a big deal when you're using that tap to turn on/off a relay, but you don't really want to be drawing current to actually power your accessories.

Doing it properly does require running a wire through the firewall. There is a big rubber grommet (with all kinds of OEM wires running through it) in the driver's side footwell area that you can use. I've ran several wires through there without a problem. Puncture a hole in the grommet if you have to.

Have a look at this thread: https://www.tacomaworld.com/threads/wiring-an-aux-fuse-block-relays-and-switches-in-a-2016.401253/
... it'll show you photos of a proper setup.

Battery positive ->

$47 Bussmann CB185-100 100 Amp Type III Circuit Breaker

100amp circuit breaker input -> circuit breaker output (usually labeled "aux") -> positive terminal on

$27 Blue Sea Systems 5026 ST Blade Fuse Block 12 Circuit with Ground and Cover

BlueSea fuse block. Since that CB is rated for 100amps (theoretical maximum total for all accessories drawing from your fuse block), you need at least 3AWG copper wire between the battery, circuit breaker and fuse block. Thicker (2AWG, 1AWG, 1/0, 2/0, etc.) would be even better. If the wire is aluminum, it'll need to be even thicker.

The fuse block's negative should run to a ground on the chasis (use the same, thick wire). Then all your individual accessories would connect to the fuse block and have their own fuses, neatly managed in that fuse block. Each circuit would be protected, and nothing would be drawing current through any of the truck's original wiring.

// edit - as always, don't forget to disconnect the battery's negative terminal before doing any electrical work.

 

Thanks for this. I have been following this thread for a while and I am about to purchase everything you mentioned.

My only question is how can I achieve factory functionality without tapping the factory wires? I understand that I can put everything on its own switch, but having my cargo light and bed lights on one switch is super convenient and I really like that they go on with the key fob.

 

or you could run a separate fuse panel under the hood and run the wire (fused) to the rear and not worry about shorting the Body Control Computer.

 

With this wiring (tapping the relay into the blue wire (pin 5) on the switch connector), when you turn on the factory bed light switch, it turns on the aftermarket bed lights, right?

I'm still not clear whether the bed lights turn on when you unlock the truck using the key fob (since the factory bed light normally turns on like this). This will maintain the OEM behavior, right?

 

See my "Current Configuration" above. I guarantee it will work with the factory cargo switch in the same fashion. I have not tried to hook up the relay yet, but the other gentlemen on this post say it will work. It's worth a try if it will make my hook up safer.

 

Have any of you considered mounting a hood pin switch in place of installing a switch in the bed? Something like

$7 2-1/2" Adjustable Pin Switch

this might be able to conveniently activate you led bed lights every time you open the tailgate. You could still mount a switch if you are constantly hauling stuff with your tailgate down for a manual shut off. So you don't kill your battery when you park your taco. If there are no decent mounting options for this type of switch, maybe a

$20 Magnetic Switch, Standard Packaging,Black

magnet switch would be easier to install on the bottom of the tailgate and back lip of the bed, so they are in contact whenever your tailgate is open?

 

I thought I posted this already...
I tapped into the blue wire and tested it with a voltmeter, and when the cab light switch is set to off, I get 12V, but when it is On/Door (with door open), I get 0V. This seems backwards from what I want b/c I want my lights to turn on when the switch is set to On/Door. I noticed that the OP said to connect the negative from the lights to the blue wire so I'm a little confused. I tried to understand the wiring diagram and I'm not understanding it...

 

Just want to confirm u tapped the - negative connection from the bed lights to the blue wire from the switch. And the + positive wires from the lights to the inline fuse to the battery. If this works and has not given you any problems I will be doing this also.

 

The configuration is just as you see it in the picture. I did NOT add in the relay because the draw from the added lights was so minimal. I didn't necessarily use an inline fuse though. I used an add-a-fuse and connected straight into my fuse box below the steering wheel.

 

@Corneeeeelius What fuses did you use on your add a fuse? I know one is 7.5 but what is the other?

 

I think it was just whatever came with the add a fuse. Probably a 10 amp.

I actually pinched one of the wires in my truck bed while trying to tuck them underneath the bed rails. It shorted and there was a small spark and I lost functionality. I repaired the wire with some butt connectors and then replaced the the fuse with whatever I had on hand. I think it was either a 7.5 amp or 10 amp. I say all this to show that a 10 amp will do. The fuse did exactly what it was supposed to and protected my fuse box.

 

The proposed circuit with the relay didn't work for me. Anyone do this and get it to work with factory wiring?

 

I never used the proposed configuration, but the “current configuration” eventually burned out my factory switch and had to replace it. Within a week the replacement switch burned out too. Looks like the draw from the added lights IS too much for the system to handle. I will wind up hard wiring the added lights to a separate switch located in the truck bed so that the lights don’t come on with the factory switch anymore.

I should have listened!