# Wiring in aux lights using factory aux switches- 2016 F350



## mkwl

Hey Guys-

New to the Ford world- I'm looking to wire in two auxiliary LED backup lights into the rear bumper of my new 2016 F350 gas pickup. Can someone shed some light on where to tie into the factory switches? Relays in place already? 

Thanks!

Matt


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## unhcp

the wires are under the dash should be tapped off,

https://www.fleet.ford.com/truckbbas/non-html/Q-117R2.pdf

Switches Circuit Color Fuse # Rating
Aux 1 CAC05 Yellow F94 25A
Aux 2 CAC06 Green/Brown F95 25A
Aux 3 CAC07 Violet/Green F9 10A
Aux 4 CAC08 Brown F2 15A


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## RMGLawn

Use the pass through wires in the engine bay too so you don't have to go through the firewall.


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## Brian Young

Matt, do you want them to come on with just reverse or do you want to control when they come on.


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## Too Stroked

RMGLawn;2088701 said:


> Use the pass through wires in the engine bay too so you don't have to go through the firewall.


Is that new? I always used the ones under the dash. Of course I always had many kind words for the bean counter at Ford who decided that and extra inch or so of wire would be too costly too.


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## RMGLawn

Too Stroked;2088950 said:


> Is that new? I always used the ones under the dash. Of course I always had many kind words for the bean counter at Ford who decided that and extra inch or so of wire would be too costly too.


You still have to connect the pass through wire to the aux switch, but you only have to bring the light wires to the fuse box area under the hood as they are stuck back there on the harness.


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## 1olddogtwo

Too Stroked;2088950 said:


> Is that new? I always used the ones under the dash. Of course I always had many kind words for the bean counter at Ford who decided that and extra inch or so of wire would be too costly too.


It's a game they play called "hide and short". One of the best thing Ford ever did and made it a b!tch to find and connect!

The 2017's will have 6 switches up by the dome light, can only guess where they put the wires.


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## mkwl

Brian Young;2088776 said:


> Matt, do you want them to come on with just reverse or do you want to control when they come on.


I had them come on just in reverse on the last truck but I'd really rather them be on all the time when I switch them on to help illuminate the back of the truck a little better when we're salting, shoveling, etc.


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## mkwl

So if I'm understanding this correctly, all I have to do is run a ground, run a wire up the frame rail into the engine bay, connect to one of the four wires taped off near the fuse block, flip the switch and voila? Or is there another connection that needs to be made in the cab?


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## RMGLawn

Whatever wire you tap into in the engine compartment, that same color wire needs to be connected to whatever aux switch wire you choose under the dash by the emergency brake pedal as well.

Then flip the switch and bam. 

Also if you mount the lights to a metal part just ground the negative to the bolt for the light.


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## Brian Young

mkwl;2089124 said:


> I had them come on just in reverse on the last truck but I'd really rather them be on all the time when I switch them on to help illuminate the back of the truck a little better when we're salting, shoveling, etc.


You'll have to complete the loop so to speak like RMGLawn said. If your just running a couple led lights I'd just use one of the 15 amp switches and save the bigger ones for something else.


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## dlcs

I was getting ready to ask the same question. Bought a 2016 f 250 last month and had the same question. Dealer told that the 3 and 4 switches are 30 amp? Also I need side steps, what's good?


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## Derek'sDumpstersInc

I have mine wired so that they come on whenever the vehicle is put into reverse, but also through one of the upfitter switches so that I can turn them on and use them as work lights and for spreading. I didn't do the work, my upfitter did it when they built the truck and I can tell you that they had to play with it quite a bit and even install some relays or something as well in order to get it all to work properly. Because I have a backup alarm on my truck, it took some work in order to get it to work correctly without the alarm sounding every time I flipped the switch on.


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## Brian Young

dlcs;2089536 said:


> I was getting ready to ask the same question. Bought a 2016 f 250 last month and had the same question. Dealer told that the 3 and 4 switches are 30 amp? Also I need side steps, what's good?


I went to runningboard warehouse for my steps. great prices and selections.


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## tawilson

mkwl;2089128 said:


> So if I'm understanding this correctly, all I have to do is run a ground, run a wire up the frame rail into the engine bay, connect to one of the four wires taped off near the fuse block, flip the switch and voila? Or is there another connection that needs to be made in the cab?


If it's like the 2015, you will find a bundle of 8 wires under the dash to the left side of the steering column. 4 of those are the pass through wires. Then tucked up even further you will find 4 wires that are connected to the auxiliary switches. And yes, another couple inches of wire would have been nice.


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## 04fordf350

is it like that on an '11 too? I saw the bundle below the Aux wires but i thought those were for a high idle control. And where exactly are the pass through wires located in the engine bay? I could never find those.


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## tawilson

04fordf350;2094657 said:


> is it like that on an '11 too? I saw the bundle below the Aux wires but i thought those were for a high idle control. And where exactly are the pass through wires located in the engine bay? I could never find those.


On mine they were between the fuse box and the firewall. And weren't easy to find.


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## 04fordf350

tawilson;2094660 said:


> On mine they were between the fuse box and the firewall. And weren't easy to find.


ok thanks. If i have to do anything else i will look for them again. I ended up just cutting into the grommet and running wires through there.

I also drilled a hole underneath the truck right next to the door sill. Makes a perfect place to run many wires because of the harness and cable management trays that are under the door sill plate.


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## Taxbully

Derek'sDumpstersInc said:


> I have mine wired so that they come on whenever the vehicle is put into reverse, but also through one of the upfitter switches so that I can turn them on and use them as work lights and for spreading. I didn't do the work, my upfitter did it when they built the truck and I can tell you that they had to play with it quite a bit and even install some relays or something as well in order to get it all to work properly. Because I have a backup alarm on my truck, it took some work in order to get it to work correctly without the alarm sounding every time I flipped the switch on.


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