Ok, so I got a pair of auxiliary LED lights off my old truck that I had "hidden" and found in the shed last weekend. I mounted them to either side of the license plate (in the front) and ran ground to the battery. What I'd like to do is run power to a circuit that comes on and goes off with the ignition switch. In my old truck, I'd achieve this by running power to the ignition side of the starter solenoid, but this new-fangled 2012 F150 doesn't have that solenoid anymore. So what circuit would yall run it to? Can I even tie into the ignition circuit or is that too much to ask nowadays? Any help would be greatly appreciated!

 

With my very low power Raptor lights I just used a piggyback super mini connector to power them and tested a fuse that was hot with the key on and off when the key was off.

If your lights draw a lot, you are going to want to use a relay, and use a piggyback fuse as the "turn on" for the relay. So the wire from the fuse would go to #86, ground #85 to chassis as close to light as possible, #30 from battery, and #87 to your auxiliary lights.

http://codecookbook.co/rib-relay-wir...wire-with-rib/

 

When you say "very low power", what are we talking? I'm looking at about 18W for these lights (+/- 2W, as I cannot find the exact order/data when i got them years ago).
I can certainly see using a relay to power them, as I don't think any circuits that i find to tie into are going to be high enough power to run these without blowing some fuses. As far as I can tell, any circuits in the fuse box are going to have that delay-off that everything else seems to have when i turn off the key. I'm looking more for direct-correlation of Lights On --> key in "Run" position, Lights Off --> key in any other position.

 

The lights are something like 0.5 watts each I believe, so 1.5 watts total. They are the direct correlation you are talking about, key on = lights on, key off = key off. No in between. Also when I remote start the truck they come on because the engine is on. I can find the fuse # I used later on for you, if you'd like.

 

Run a relay, so the only power on the factory circuit is what the relay draws. Tap the relay actuation into your ignition switch Purple wire with green stripe. Pull the lower plastic cover off by your knees, then pull the metal plate, then remove the three screws under your steering column and remove the plastics around the steering column. The ignition switch is a black 7 pin connector on the left side of the column. From the bottom of the connector, the second wire from the bottom should be Purple with a small green strip, this is your accessory power wire (switched power - only powered when the key is on). its a small wire, so be careful.
As long as your running a relay you should be good.

 

A relay (with an appropriately fused supply) is the way to go. A typical 20A accessory relay pulls about .16A /2W, so almost nothing.