I am soon going to install a LED bar on my Hyundai Tucson 2006. I want the lights to go on whenever the high beam is activated. I have located the fuse for the high beam, and intend to use an adapter to steal the signal from this circut. Using a relay of course.

I have read that a lot of people power their LED bars by tapping into the positive cable which powers the high beam lights. I would like to avoid this as it would mean cutting into the neatly packed wiring. Is it possible to connect the power source cable to my LED bar directly to positive on the battery, bypassing the cable powering high beam lights?

2 Answers 2


In general, if you can connect the LED bar directly to the cables to the lights, you can also wire it directly to the battery. But a car battery has enough power to easily melt a wrench touching both terminals. If there's a short circuit in the LED bar or somewhere in the cable, this can easily start a fire. You should have a fuse close to the positive battery terminal in your cable to be safe.

And anything being connected directly to the battery can drain it. But if the relay disconnects the LED bar completely, this is fine.

  • Perfect. Now I'm planning to connect it directly to the positive on the battery then, with a proper fuse close to the pole. Excellent answer! Commented Oct 21, 2020 at 7:12

If you want to power your LED bar on together with the high beams the correct way is to connect a relay to your high beams, and have it turn the LED bar on/off. The power can be taken directly from battery terminals - just remember to install a correctly rated fuse between the battery positive terminal and your circuit. Make sure the wiring you're going to use is of proper gauge and designed for outdoor use (most importantly, insulation is UV-resistant so it won't start cracking after a year of regular sun exposure), all connectors are protected from the elements and nothing rubs against sharp edges.

Also might be a good idea to add a switch in series with the relay coil so you can turn off the lightbar even with your high beams on. In many countries it is not legal to use additional light sources while on public roads, so better check your local regulations.

  • Thank you for your answer! I think I will connect the on/off switch on the bar with a "double fuse" to the input signal for high beams on/off. Then I will connect the bar directly to battery positive, with a proper fuse close to the positive pole on the battery. It -should- work I think, and I'll avoid having to cut into the neatly packed cables of the positive coming to the main high beams. Commented Oct 21, 2020 at 6:32

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