ibd2328

iTrader: (2)

23234

ibd2328

iTrader: (2)

Needed to add I used SPST 5pin relays (normally open). This diagram will not work with Normally Closed relays.

bobkyle2

Moved into how to section

ibd2328

iTrader: (2)

Thanks bob

Fordman46

So I know a good amount of wiring stuff as I have wired all my own lights/radios/etc on my truck. But what is the function of using a relay?

ibd2328

iTrader: (2)

Lots and Lots of uses.
Why do I want to use a relay and do I really need to? Anytime you want to switch a device which draws more current than is provided by an output of a switch or component you'll need to use a relay. The coil of an SPDT or an SPST relay that we most commonly use draws very little current (less than 200 milliamps) and the amount of current that you can pass through a relay's common, normally closed, and normally open contacts will handle up to 30 or 40 amps. This allows you to switch devices such as headlights, parking lights, horns, etc., with low amperage outputs such as those found on keyless entry and alarm systems, and other components. In some cases you may need to switch multiple things at the same time using one output. A single output connected to multiple relays will allow you to open continuity and/or close continuity simultaneously on multiple wires.

quadracer960

thanks

ibd2328

iTrader: (2)

Welcome... The write up looks alot more difficult than in reality. Let me know if how it works out for you.

jcope3193

Great thread and exactly what I have been looking for the past couple months.

I have put a flat work bed on my truck and it came with LED lighting that plugged right into the truck's factory harness. There are two reverse lights on the bumper and on a headache rack at the top of the cab. I want to be able to turn them on without being in reverse, just as you have described, but didn't know if I needed to still add the relay since they are LEDs. Would there already be a relay in the truck somewhere that I just need to connect the aux on switch to?

I do not want to add lights, just turn on the bright LED reverse lights that are already there with the flip of a switch, anytime.

Would there be any harm done if this aux switch was on and the truck was shifted into reverse sending a second power source to the relay or lightheads?

Thank you from a newcomer!

BlueSpark

Thanks for the great write-up. Ignore my previous post, pre-edit. I re-read this and it makes sense to me now!