2021 Bronco AUX Switches Wiring Diagram, Video, Discussions

[Techun]

I've done all of my own wiring for many years now. Everything I've done goes through relays and switches to control them. Either the video is confusing or Ford's wiring is confusing. All of those wire connections should already be done. I don't get it.

What wire connections should be done? It's all set up for you, just waiting your loads.

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[Techun]

Is it too much to ask for this guy to spit before filming a video?

 

[peta8368]

Okay I see what you’re saying.
So since the circuit D & E wire endings are in the glovebox...hypothetically if you wanted to connect an Aux switch directly to D or E you would have to run your own wire from that Aux switch to each of those circuits (meeting them in the glovebox and not in the engine bay like B1, B2, and C).
That way you could still maintain separate use of all 6 Aux switches?

B1 and B2 goes from engine bay to under dash. D goes from under dash to passenger side visor. E goes from under dash to passenger side hatch.

so to wire something to hatch, you'd connect switch wire (in the engine bay) through B1 (or B2), to under dash, THEN connect that B1 (or B2) to E, which brings the power to the hatch area.

The only part that "consumed" the switch is how you connected one of the 6 to B1 (or B2) in the engine bay. You would have 6 switches regardless.

The only reason you'd run your own wire to under the dash area is if B1 and B2 are both used already, and you need a 3rd circuit to or through that area.


Peter

 

[VoltageDrop]

Are you sure? If true, that seems kinda silly.

It does look like that from the video. They're probably banking on you using half of them at the front bumper or for something mounted in the engine bay. Seems reasonable. You can always run a wire down the frame rail from the engine bay if you really need something else toward the rear. The meat and potatoes here is having 6 switches already wired with fuses and relays.

 

[Thed]

This video created more questions for me than it answered. Cool that there's a few pre-run circuits, though.

 

[Portapot]

Hmmm...so if you wanted to power an aftermarket amplifier I assume you could use one of these prerun wires, probably the one in the rear for the minifridge, to drive it rather than having to run a new wire for power? Sound feasible or is that a dumb idea? Any thoughts?

 

[peta8368]

Are you sure? If true, that seems kinda silly.

my understand is the same as mjcutri. There are technically 3 circuits leading away from the engine bay (B1, B2, and C). So saying there are 5 circuits leading to various points on the car is a bit misleading.

 

[peta8368]

Hmmm...so if you wanted to power an aftermarket amplifier I assume you could use one of these prerun wires, probably the one in the rear for the minifridge, to drive it rather than having to run a new wire for power? Sound feasible or is that a dumb idea? Any thoughts?

Honestly, these wires look very small to be powering something such as an amplifier. Unless you are talking about a small amplifier 100w or less.

I don't see how a thin wire like that can pull 25 amp... (aux 1)

Peter

edit: here's some reference charts. 25A requires 12 AWG. and 12 AWG has wire thickness of 0.08 inch (just over 5/64), or 2.05mm in metric. I may be way off eyeballing the wires in the video, but it doesn't look anywhere near thick enough.

 

[imnewtothis]

B1 and B2 goes from engine bay to under dash. D goes from under dash to passenger side visor. E goes from under dash to passenger side hatch.

so to wire something to hatch, you'd connect switch wire (in the engine bay) through B1 (or B2), to under dash, THEN connect that B1 (or B2) to E, which brings the power to the hatch area.

The only part that "consumed" the switch is how you connected one of the 6 to B1 (or B2) in the engine bay. You would have 6 switches regardless.

The only reason you'd run your own wire to under the dash area is if B1 and B2 are both used already, and you need a 3rd circuit to or through that area.


Peter

Hmm...I see your logic...but at that point why have B1 and B2 separate from E and D at all?
At that point you would only have 3 pre-made circuits (circuit C leading to the grill, circuit B1+D leading to the rear, circuit B2+E leading to the roof)...leaving 3 open Aux switches where you would have to run your own wire to wherever you choose?

I can see that.

I can also see running separate wire from each of those Aux switches to each respective circuit like my 2nd grade macaroni art level diagram showed lol

But alas...it seems I may be missing a bigger picture here! If the consensus is the diagram is wrong please let me know and I'll be sure to take it down!

 

[MVP]

They put up an article with this info too. It's pretty detailed.
https://community.thebronconation.com/how-to-use-the-auxiliary-switches-on-your-bronco/

Thanks for posting that. It makes more sense now.

if everyone looks at my screen grab you will see all of the wires on the left are from the power distribution box. It’s confusing how they explained 5 wire runs. Really they should have said you have 3 wire runs from the engine bay.

On the right you can see that there are three separate wires. 2 run to the passenger glove box and 1 goes to the grille.

At the passenger glove box you can connect to one wire that heads to the rear and one wire that heads to the roof.

All of the wires that are pre-run(not the ones coming out of the distribution box) can handle 25 amps.

I’m not amazing at electrical but to me that says you can connect a 25A wire from the box to one of the pre runs that run to the passenger glove box and you could connect the rear and the roof wires to the one wire as long as the combined draw is still 25A or under.

That would have one switch control both things and would still leave you a pre-run wire in the glove box.

the other wire you would have to run your own connected to somewhere else.

Or simply use one passenger wire to rear and one passenger wire to roof and they will be on separate switches. For any other accessories you will have to run your own wire the rest of the way.

So you have three pre run wires really and three others you have to do yourself.

something like fog lights and flood lights on the front you should easily be able to do yourself and you wouldn’t need to run wires inside.

Edit:
I think I’m wrong about the prerun wires being able to handle 25A. I only said that because that’s what they used to come off of the box but maybe with the distance you need a thicker gauge wire. I’m not sure.

 

[peta8368]

Hmm...I see your logic...but at that point why have B1 and B2 separate from E and D at all?
At that point you would only have 3 pre-made circuits (circuit C leading to the grill, circuit B1+D leading to the rear, circuit B2+E leading to the roof)...leaving 3 open Aux switches where you would have to run your own wire to wherever you choose?

I can see that.

I can also see running separate wire from each of those Aux switches to each respective circuit like my 2nd grade macaroni art level diagram showed lol

But alas...it seems I may be missing a bigger picture here! If the consensus is the diagram is wrong please let me know and I'll be sure to take it down!

You can also run B1 + custom pull to the dash area for accessory rail, or B1 + custom pull to a CB mounted inside the glove box.

I imagine that's why B1 and B2 terminates by the glovebox, and not directly to the hatch or visor.

Peter

 

[Tdifonzo]

I was excited I could plug a powered sub into the rear until I remember I’d still have to run audio wires. lol

 

[Dimitar]

Hold it, what about the lights that were mounted to the cowl next to the sideview mirrors??? I’ve seen some prototypes sporting them, don’t tell me I have to drill another hole in my firewall

 

[Hoofnmouth]

Impressive... based on previous replies, I'm sure you did help some folks figure this out.


Yeah, especially when running through the structure that keeps water out of your lap

For those who don't speak metric area, 1.5mm^2 is 14 AWG, 0.75 is 18 AWG, and 0.35 is 22 AWG.

And a dab of silicone selant wont hurt either

 

[mjcutri]

Hold it, what about the lights that were mounted to the cowl next to the sideview mirrors??? I’ve seen some prototypes sporting them, don’t tell me I have to drill another hole in my firewall

No, I bet you can fish wires up to those points from the engine bay pretty easily.

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