How to properly hardwire interior devices?

I wanted to know what is the proper way to hardwire interior devices? More specifically I want to hard wire some interior LED lights and a dashcam. I’ve watched a few videos online but they never explained which way it should be done.
From what i know there are two ways to do it.

  1. Hardwire to fuse box
  2. Hardwire to battery with an inline fuse.

Which is correct (more safe and reliable)?

Both can be safe and reliable. However, if you go to the battery, you have to fish your wires through a bulkhead seal in the firewall and run your wires much further. Depending on how much power you’re drawing, that may require larger gauge wires than if the run was shorter from interior fuse panel. Fuse panel is less work, less chance of leaks and less expensive materials…

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ok, I think ill probably be going with the fuse option. One other question, how do i choose amp fuse to go with?

The instructions for the devices should tell you what size fuses to use. Remember, the purpose of the fuse is to protect the wiring from overheating and possible fire, not to protect the device.


There might be unused fuse slots in the fuse box. There should be a fuse map in the inside of the fuse box cover. See if that is an alternative.

That all depends on what you want the LED lights to do, under what conditions to turn on and how many LEDs. Most cams come with a connector that plugs into the cigarette lighter, which in most cases is sufficient.

If you wish to hide all the wires, you could connect the cam to the cigarette lighter’s wiring in the back. For the LEDs it all depends on what kind of LEDs, inside or outside?