Ok I have a set of small led fog lights I have had for some time and a just bought a 12'' bar light to go under the sling. these two came with the wiring harness which has a relay on it and I have another set of round led lights that did not come with a wiring harness just he hot and ground wire. I have these hooked up and just hit me, is the relay really necessary? the set with out the relay works just has good as the ones with the relays. if the relays are not REALLY needed it would clean up a lot of wiring for me. they are all on a single switch with a inline fuse. I mean each light has its on switch. So to all the electrical guys are theses relays needed. or what is the purpose for theses? thanks. here are the round ones I have with no relay.
LED aftermarket Lights ie; the bar and fog light wiring
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The purpose of a relay is to take the current load off the switch, protecting the switch. On headlight circuits with Halogen or old-style incandescent bulbs, with 4 headlights, each needing 55 or more Watts, the switch would need to be able to handle around 18 Amps (I assumed 12V for ease of math).
Here's the math - 4 bulbs x 55W = 220W. Using 12V, this means a current of around 18.3Amps (220/12= 18.33 Amps). Since LED bulbs typically use 1/4-1/2 the current needed for incandescent bulbs, you may find the switch that can handle the needed current w/o problem, but using a relay is still preferred since the switch will last a lot longer compared to not using a relay. Using a relay means the switch only sees a few milliamps instead of the entire current load of the circuit and will therefore have a much longer life. -
Not a wiring guru but know enough to get me into trouble. You didn't mention where you're getting your power from, if it's one of the lighting circuits on the sling then you're going through a relay already. If I'm wrong someone please school me.
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The purpose of a relay is to take the current load off the switch, protecting the switch. On headlight circuits with Halogen or old-style incandescent bulbs, with 4 headlights, each needing 55 or more Watts, means the switch would need to be able to handle around 18 Amps (I assumed 12V for ease of math).
Here's the math - 4 bulbs x 55W = 220W. using 12V, this means a current of around 18.3Amps (220/12+ 18.33 Amps. Since LED bubls typically use 1/4-1/2 the current needed for incandescent bulbs, you may find the switch that can handle the needed current w/o problem, but using a relay is still preferred since the switch will last a lot longer that compared to not using a relay. Using a relay means the switch only sees a few milliamps instead of the entire current load of the circuit and will therefore have a much longer life.Thank you for the information. Always liked the idea of playing it safe, so the relays will stay. Thank you again Sir.
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Not a wiring guru but know enough to get me into trouble. You didn't mention where you're getting your power from, if it's one of the lighting circuits on the sling then you're going through a relay already. If I'm wrong someone please school me.
I have a fuse block installed so not using the factory plugs for anything.
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I have a fuse block installed so not using the factory plugs for anything.
Got it. BkL gave good advice above.
I'm running some similar lights in the factory position off the factory wiring and just breaking the ground with a switch.
I think you'll be impressed with the lights!
