Aux lights on own circuit - relay needed?

[chefduane]

I intend to install some aux LED light strips on the front of the Ex. They both draw 55w. They will operate independently of any other lighting. As long as I put them on their own switched circuit and use an inline fuse, would there be a need for a relay?

 

[Gadget X]

A relay will keep the lights from drawing all their power through the switch, so I would suggest using one. It's added insurance against frying something or shorting something out. The relay will transfer the power to the lights, using the switch as just a low-amp input.

 

[drdoom]

I would use a relay. Edit: and do...I have added in two relays so far, for rear off road LEDs, and for halogen driving lights.

 

[koda2000]

don't know that LED's would need a relay (it's all about amps) but it couldn't hurt to use one. i would install a relay and a fuse just to be on the safe side.

 

[chefduane]

Yep, I think a relay is the way to go. There are many (!) wiring diagrams on the site but cannot find a specific one on how to wire in a relay on a dedicated circuit WITH a 3 position lighted switch. I'm no electrician or car wiring guru but a simple wiring diagram would help. Anybody know where one is located?
Thanks!

 

[koda2000]

on the back of the package the relay comes in (HELP section type relay) there's usually a diagram showing how to wire it. it will have numbered terminals (eg: 86,85,31). i'm sure you could Google it too (example link below). basically power flows from your switch to the relay to turn it on (energize it). the relay needs a ground and it's own power supply. when the relay is energized, it makes a connection from it's power supply and transfers it to whatever you're trying to power. these wires would be heavy gauge. in this way you can power a high amp device using a puny switch with thin wires. i don't think you can have this work with a 3 position switch w/out using multiple relays. even then the relay would always be transferring 12+ volts. i'm not sure what your 3 position switch is supposed to do.

http://www.ehow.com/how_4912752_wire-automotive-relay.html

 

[chefduane]

on the back of the package the relay comes in (HELP section type relay) there's usually a diagram showing how to wire it. it will have numbered terminals (eg: 86,85,31). i'm sure you could Google it too (example link below). basically power flows from your switch to the relay to turn it on (energize it). the relay needs a ground and it's own power supply. when the relay is energized, it makes a connection from it's power supply and transfers it to whatever you're trying to power. these wires would be heavy gauge. in this way you can power a high amp device using a puny switch with thin wires. i don't think you can have this work with a 3 position switch w/out using multiple relays. even then the relay would always be transferring 12+ volts. i'm not sure what your 3 position switch is supposed to do.

http://www.ehow.com/how_4912752_wire-automotive-relay.html

Perhaps I used incorrect terminology. It is a regular On/Off lighted switch with 3 spade type connection terminals on the rear.
I'll keep looking for a wiring diagram. Most all examples I find are how to wire lights into an existing system.

 

[DjDom]

To be honest, you'll be fine running it without a relay. Just make sure it's a high amp quality switch. The switch should be able to handle a 20 amp draw from those lights, just get a good 30 amp switch.
I have 2x55 watt Aux lights on a single switch for a while now, and have no problems. No relay either. Just make sure you turn them off before leaving the truck.

 

[chefduane]

To be honest, you'll be fine running it without a relay. Just make sure it's a high amp quality switch. The switch should be able to handle a 20 amp draw from those lights, just get a good 30 amp switch.
I have 2x55 watt Aux lights on a single switch for a while now, and have no problems. No relay either. Just make sure you turn them off before leaving the truck.

That's exactly what I was thinking. I just figured I should use a relay based upon various postings here that strongly suggested using a relay. But as long as I use the appropriately sized wiring/switch/fuse it should be ok.
I did find a schematic on how to wire in a relay but I'm thinking I may not use one.

 

[DjDom]

Relays are mostly when using low end/low amp switches with high amp circuits.
Wipers are a good example, you don't want the current of 2 wiper motors going through that tiny switch.

 

[koda2000]

if not using a relay and you find the wiring and switch get hot... you need a relay. if they stay cool/slightly warm you can get away w/out using one. your 3 terminal switch does not equal 3 position switch. it's just ON/OFF with a light to indicate on. in that scenario, one relay would suffice.