Adding USB and 12v Cig outlet

[dudmleh522]

Hey guys on my 2018 SCREW with 802A, I am planning to add a USB and 12v outlet on top of the center dash (behind my built right phone mount)
I am thinking of using a add a circuit and tap it into passenger side fuse box.
I want this to be on al the time hoping to use a constant power. Any suggestion on which fuse to tap into? and which fuse amp should I be using for the project?

By the way I am already using 36 for my ham radio.

Passenger compartment​

№	Amp Rating	Protected components
1	10A	Demand lamp relay. Power seats relay. Glove box. Vanity lamps. Overhead console. Dome. Courtesy. Map lamps.
2	7.5A	Memory module logic. Memory seat switches. Lumbar motor.
3	20A	Driver door lock motor.
4	5A	Trailer brake control.
5	20A	Not used.
6	10A	Not used.
7	10A	Not used.
8	10A	Not used.
9	10A	Not used.
10	5A	Not used (spare).
11	5A	Combined sensor module.
12	7.5 A	Climate head module. Smart datalink converter.
13	7.5 A	Cluster. SCCM.
14	10A	Brake.
15	10A	Smart datalink converter.
16	15A	Tailgate release.
17	5A	HUD.
18	5A	Ignition switch and passive-entry passive-start start stop switch. Key inhibit solenoid.
19	7.5 A	Tow haul (O/D) cancel for floor or column shifter.
20	7.5 A	Not used.
21	5A	HUD. In car temperature with humidity sensor.
22	5A	EPB. Power seat.
23	10A	PDRG switch. Inverter. Driver side window. Moonroof. Vista roof.
24	20A	Central lock/unlock.
25	30A	Driver door control module.
26	30A	Passenger door control module.
27	30A	Vista roof. Moonroof.
28	20A	Not used.
29	30A	Not used.
30	30A	Not used.
31	15A	Adjustable pedal switch and motor.
32	10A	Multi-function display. Global position system. Sync 1. Sync 2. Radio frequency receiver.
33	20A	Radio.
34	30A	Run-start relay.
35	5A	Restraints module.
36	15A	360 camera module. Heated steering wheel module. Rear-view mirror. Rear heated seats.
37	20A	Power distribution box run-start fuses.
38	30A Circuit breaker.	Rear window switches and motors.

 

[JAndreF321]

I'm planning on doing this today or tomorrow also. You figure it out? I'm using 36 for an ignition signal for my dual battery so that is out. Are 28-30 under ignition only?

 

[FordTechOne]

I would advise against any add-a-fuse products. The fuses, terminals, and circuits in the BCM are only designed to support the load of the factory components. The add-a-fuse draws from the same source, which can result in the total draw exceeding the nominal rating. Not only that, but modules are very susceptible to voltage variances, so fuses powering modules should never be tapped into.

 

[JAndreF321]

I would advise against any add-a-fuse products. The fuses, terminals, and circuits in the BCM are only designed to support the load of the factory components. The add-a-fuse draws from the same source, which can result in the total draw exceeding the nominal rating. Not only that, but modules are very susceptible to voltage variances, so fuses powering modules should never be tapped into.

Thanks for the feedback. You think that it's also bad for signal wires running to relays or DC-DC chargers? I usually see people do inline taps off of ignition-on wires so I thought fuse taps wouldn't be an issue. I'd rather not run a wire from the alternator...not even sure how that would work without looking at it.

 

[FordTechOne]

Thanks for the feedback. You think that it's also bad for signal wires running to relays or DC-DC chargers? I usually see people do inline taps off of ignition-on wires so I thought fuse taps wouldn't be an issue. I'd rather not run a wire from the alternator...not even sure how that would work without looking at it.

The safest method to use a signal wire is to splice into it with a solid state relay, so there is no added load on the factory circuit. But that of course is dependent on the type of circuit, the installers’s skills, and where the splice is added. Personally I don’t recommend splicing into any factory circuits, I’ve seen too many issues caused by electrical modifications.

As far as the circuits from the ignition switch, they do not carry a load; nothing should be added to them. Like the majority of switches, they are used to provide a signal, not power any components.