Using factory pre-run wires for always-hot accessory power (bypassing upfitter switches)?

[murrman]

Curious if anyone has experience using the factory pre-run wires (the non-powered ones that run between various locations in the Bronco) to power accessories directly, bypassing the upfitter switches entirely.

My goal is to power a Starlink Mini hardwired with my own inline switch so I can run it with the vehicle off. I’m not worried about battery drain since I have a shore power charger keeping the factory battery topped up when parked. The upfitter switches being ignition-controlled rules them out for my use case.

A few specific questions:

1. Has anyone connected one of the pre-run wires (cargo area, glovebox, A-pillar) directly to a power source like a fuse block or battery, completely bypassing the upfitter system?
2. Any real-world issues using these wires for a low-draw accessory, given the 16 AWG limitation?

I know the cleaner solution is just running my own wire from the battery, and that may be where I end up. But I’d like to understand whether the factory pre-run wires are a viable shortcut before I rule it out. Thanks.

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[Brian_B]

Sure, they would work fine for a starlink. They are just pre-run wire, there's absolutely nothing special about them. They don't have fuse links or anything. Starlink is a pretty light load (maybe 2A) and that gage wire will be fine.

You could probably do the entire thing without splicing a single non-OEM wire if you wanted to... but practically, the one going from the upfitter area under the hood, through the firewall, and coming out by the passenger footwell is probably the only one that's really useful - splice from the upfitter area to the battery in the engine compartment (put your fuse there at the battery), then splice from the footwell up to your switch, then back down along the sill back to wherever you are setting up your Starlink. Ground it in the back someplace convenient.

You already mentioned what myself and everyone else is going to say - at some point, you will drain your battery by accident going with a load straight to the battery. But there's no technical issues doing so, other than remembering to turn off the switch.

 

[Neigh]

The upfitter switches being ignition-controlled rules them out for my use case.

Check your owner's manual. I'm pretty sure that I read that you can swap a fuse to a different slot and it will convert the upfitter switches always hot.

 

[coadr]

I’ve got the exact setup you described with a Starlink mini! I’ve got it running off a switched cigarette plug in the back.

Originally I had asked around the local 4WD shops (we have a bronco specific one here in Denver) and no one really wanted to do the wiring. They were all concerned about fire hazards. The switched outlet works well, I just disable auto start stop when I’m using it because the engine turning off tends to cause the dish to restart

 

[brkdncr]

I’d consider getting one of those built-in batteries for the mini to avoid issues with power switching off, or moving it to a different power source without having to to restart it.

 

[murrman]

I’d consider getting one of those built-in batteries for the mini to avoid issues with power switching off, or moving it to a different power source without having to to restart it.

I've thought about something like the PeakDo LinkPower, but I don't think it would work with my American Adventure Lab mount. Not sure I want to completely rethink my mount setup.

 

[Phil B]

I used the upfitter wires to the passenger side rear to connect a step up power converter for my starlink. I really wish there was an easy way to make the upfitter switch always hot. From what I read, the fuse swap does not work on the (2023) Bronco. This is a major fail in my opinion.

 

[CalvinT]

Check your owner's manual. I'm pretty sure that I read that you can swap a fuse to a different slot and it will convert the upfitter switches always hot.

Not true.

You need to modify the wiring harness. Some have modified it so that some upfitter switches are always hot and some not.

 

[DeathValleyBob]

Assuming your Starlink terminal will be in the cargo area-here’s what I did for my Bodega fridge, similar load to yours, it pulls 1-2amps when compressor is running, so far the battery has handled this overnight: I used the Upfitter pass-through wires to get to the cargo area. Use an inline 10 amp fuse from battery bus to either the white/orange or gray/orange pass-through wire (located upper left firewall near the big rubber plug that connects to the cabin. The other end of this wire reappears on the right side of the right side footwell behind a plastic cover (not glovebox despite what you might read elsewhere) Connect the chosen wire to the nearby white/gray wire using a butt connector (or just solder them). These wires are very short so it’s going to be a fight here. Now the fun continues: remove the right side plastic cargo area panel that bears a cigarette lighter and the inadequate cargo light; you will break something in the process-use epoxy glue to fix. I used a dual-outlet Anderson PowerPole panel outlet for the business end. Wire up both outlets-you will thank me for this later. There is a threaded ground post in the vicinity. I used a small soldering iron to melt a hole in the plastic cover-be careful to get an exact fit. Cut off the Starlink power connector and replace with a PP connector. When you cut off the Starlink-provided power connector allow 6” extra wire and connect it to a PP connector so you can establish original connector arrangement in case you want to use Starlink elsewhere in the future. Be EXTREMELY careful to maintain polarity when doing this. I estimated 18 feet of #15 wire in the passthrough-including the fuse and ground-you will lose about 0.1Volts per amp of load.
Hope this helps

DVB

 

[cbrenthus]

Not true.

You need to modify the wiring harness. Some have modified it so that some upfitter switches are always hot and some not.

That's a shame, on Wranglers you can change the AUX switches to be always hot in the configuration.

As for moving the fuse, that is also a MOPAR thing - if I recall, you can move a fuse to make the rear 12V power port always on or on with accessory. And I think that isn't limited to Wranglers

 

[Phil B]

Not true.

You need to modify the wiring harness. Some have modified it so that some upfitter switches are always hot and some not.

If I remember right, it involves running a hot wire to the upfitters and a little reconfiguration. I've been looking for a new project to occupy myself with...

 

[CalvinT]

Look through the threads for retrofitting the factory upfitter switches. Someone talks about doing the modification. I think there are pictures.

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