I’m about to wire up some cheap Amazon LED lights under my back bumper….planning on just putting them on their own separate switch so I can turn them on/off manually as needed. Generally speaking, I know I gotta run a wire from battery to switch and switch to lights and I figure this is a relatively simple DIY project.

2 questions:

1. Do I need to wire in some sort of relay or fuse or something? If so, what specifically do I need and where does it need to go (I’d assume between battery/switch but I’m new to this stuff)

2. What size wire would I need to run? Is there a specific type of wire or just regular ol’ wire in X gauge?

Or am I better off buying a pre-made wiring harness? Looks like one can be had for $15-20 with relay, fuse and switch…

I’d go with a harness but that’s just me. I’m not very electrical savvy. I’m planning on doing the same to my truck but hooked up to reverse also.

I'd go with harness because it is simpler and by the time you purchased the items separately you would be close to the harness price.

Nilight makes a wiring harness for those lights that is without a question the easiest route to take here. I have those lights on about everything I own they are not the best but if something goes wrong just throw away and get another for $20.

I love them. Been pretty good lights for me I've got various sizes.

Getting the wire through the firewall to a decent looking switch isn’t easy…. You can tap into the reverse lights and it won’t require a switch. There’s a third option though. Tractor supply sells a remote relay for a 12v sprayer. You can mount the relay under the hood and hang the remote on the shift lever. Just a “cleaner” looking option that’s much easier to install.

Yeah, as I continue reading online, that’s beginning to look like the simplest option

Wiring Harness on Amazon

https://www.amazon.com/Nilight-Wiring-Harness-Switch-Warranty/dp/B071ZPX32N/ref=sr_1_1_sspa?crid=3RUSMQJJ50NJF&keywords=nilight%2Bwiring%2Bharness&qid=1674061511&sprefix=Nilight%2BWiring%2B%2Caps%2C84&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFNTzROVU0ySTdLSUkmZW5jcnlwdGVkSWQ9QTAyNDU4NThCN01GWTZCNVdTU1AmZW5jcnlwdGVkQWRJZD1BMDE5MDY3MzI4UldYVDlFUDY0QTUmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

If you need any of the leads longer they make extensions that plug up and will extend either run of wire. Comes with relay and switch and is actually a nice sealed harness.

The switch side is pretty long and can also be extended... but as Josh mentioned above getting it through the firewall on your particular vehicle is part of the game.

Yep, I was just looking at that one…I reckon that’s the direction I’ll go. In a perfect world I’d like them to come on with reverse lights but still have an option to manually turn them on even in Park (like for hooking up a trailer or something) but setting it up that way appears to be noticeably more complicated and I’m not that confident in my ability. So just a separate on/off switch will do for now.

You didn't mention what vehicle you are putting them on.
My F250 has upfitter switches already installed in the dash for accessories.
I connected my front light bar to one of these and although it wis a pain to wire up, it works great.

Whatever switch you use, make sure it has a light on it so you know it is on.
Nothing worse than forgetting to turn it off when not needed and then blinding people behind you on the way to work the next morning.
In this day and time, might lead to road rage.

And yes, you need a fuse or circuit breaker for sure.

F150….no upfitter switches.

Goatkiller….that one you posted looks perfect but appears to be aluminum wiring, not copper. Reckon that matters or no?

I believe the wiring Goatkiller posted is probably stainless steel.

16 AWG should be fine for LED lights.

Not afraid of ripping them off in a mud puddle?

When u finish with yours, please come kick my dog (again) for chewing the wiring up on my aftermarket backup lights and then splice them back😏.

Seriously you’ll wonder how you ever made it without them. I have some wired to the reverse switch on my ranger and backing up at night in the woods is a breeze.

So looking at that specific harness….it seems some folks had problems with it draining the battery if it sat for a few days because the light-up switch itself stays lit even when they switch is off and the key is off. So how would one wire the switch so that the switch is only lit up when the key is on?

Switch on mine has a very bright colored led light that you (should) notice if they accidentally get turned on.

My switch is only illuminated if the light switch is ON.

Says in the description "cooper" wire. I assume typo there. Would be very odd to have aluminum wire in that type harness. That is a pretty good price on a harness. I wouldn't go through the fire wall unless I could see a way that was pretty easy or not a PITA. I'd drill a hole right in the floorboard up under the piece of trim right below the door. Just make sure you secure the wire up underneath very well. Don't get them close to anything hot or sharp. I guess where you say looks like aluminum you are just seeing where it is tinned to be ready to solder. Thats why it is silver.

Yeah looks like the aluminum part was referring to an air compressor that you could select in a drop-down menu…….makes more sense

If you go this route, be prepared to splice in extra lengths of wire. I know it's different vehicles, but I just added a set of lights to our golf cart at work and had to splice in several extra feet of wire

Yeah I’m not concerned about that. I’ve done plenty of splicing/soldering and can get extra wire cheap if needed