I got four LED lights I want to wire in pairs. They are 27 watt lights and will draw 4.5 amps for two. Do I need a relay if my switch is rated at 25 amps? The company said to use a 10 amp fuse for each pair of LED Lights. Do I add a relay or run direct from the switch?

 

If it were my vehicle, even if just a matter of consistency, I'd run a relay. Generally speaking, I like to keep all the important (high amperage) electricity as short of a distance and out of the cab as I can. Do you need to run a relay for 27w LED lights? No. As a matter of good practice though and best safety, you should. Then you can easily run more lights off the same relay if you want to. Because everyone always needs more lights.

Edit: Just read you had four, not just two. Run a relay.

 

If you wife them two per switch then a really isn't really required. However, I have similar lights and I went with relays just for the piece of mind and that wa I can always switch out the lights and not worry.

 

Yes use a relay for each set, its always the safest and proper way.

 

(2) x 27 watts = 54 watts / 12 volts = 4.5 amps, as long as your switch is rated for 5 amps or more it should not be a problem (most are). You also can use 18 gauge wire.

The reason to use a relay is because it is very common to switch/wire for the minimum amperage, then later (without thinking) upgrading your 4.5 amp lights to some much higher amps and not upgrading the switch/wiring, next thing you know you are watching your jeep burn to the ground in the middle of the woods.

If you decide to wire them with a relay, the diagram below should help.