Powering a 12v Accessory Outlet from the Fuse Box?

[Mr. Keeway]

Hello all,

I'm wanting to add a couple of 12v power outlets to my car as the current ones stay on even if the car is off. This is fine for some things, but my Bluetooth audio adapter and wireless phone charger/mount are two things that don't need to be getting power when the car is off, and it's a pain to unplug them every time.

My plan is to purchase a 12v socket and connect the positive to an add-a-circuit in the fuse box, and the negative to the factory grounding location. However, I have a few concerns since I already have an add-a-circuit connected to the accessory power fuse, which is connected to the remote wire on my subwoofer amp, and the amp is grounded to the factory grounding point along with the battery. Will tapping in to my existing add-a-circuit to power both my charger and Bluetooth adapter overload that fuse slot? The fuses are 10A, the charger draws 2.4A, not sure what the draw from the Bluetooth adapter is, then there's the remote wire for the amp and whatever else the factory wiring has running through it. As for grounding, would it be a bad idea to ground it to the same spot as the battery and amp?

I'd imagine the worst that could happen is that it would just blow a fuse, but better safe than sorry so I wanted to ask here. Any input on this would be appreciated. Thanks!

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[Louisiana_CRX 5,000+ posts]

Hello all,
I'm wanting to add a couple of 12v power outlets to my car as the current ones stay on even if the car is off. This is fine for some things, but my Bluetooth audio adapter and wireless phone charger/mount are two things that don't need to be getting power when the car is off, and it's a pain to unplug them every time.

My plan is to purchase a 12v socket and connect the positive to an add-a-circuit in the fuse box, and the negative to the factory grounding location. However, I have a few concerns since I already have an add-a-circuit connected to the accessory power fuse, which is connected to the remote wire on my subwoofer amp, and the amp is grounded the factory grounding point along with the battery. Will tapping in to my existing add-a-circuit to power both my charger and Bluetooth adapter overload that fuse slot? The fuses are 10A, the charger draws 2.4A, not sure what the draw from the Bluetooth adapter is, then there's the remote wire for the amp and whatever else the factory wiring has running through it. As for grounding, would it be a bad idea to ground it to the same spot as the battery and amp?

I'd imagine the worst that could happen is that it would just blow a fuse, but better safe than sorry so I wanted to ask here. Any input on this would be appreciated. Thanks!

If you have an add a circuit relay it should be fine tapping off of it for an aux circuit ..the relay will step up the amps

 

[smichael85]

Hook up a relay to the existing add-a-circuit. Relay coil only draws 150 mA so you only need a 1 A fuse. If you are using an SPDT relay, connect terminal 30 to constant 12V (use an inline fuse holder) and tap your amp turn-on and 12V sockets off of terminal 87. The wire from the add-a-circuit goes to terminal 85 and ground terminal 86.

 

[Mr. Keeway]

If you have an add a circuit relay it should be fine tapping off of it for an aux circuit ..the relay will step up the amps

Hook up a relay to the existing add-a-circuit. Relay coil only draws 150 mA so you only need a 1 A fuse. If you are using an SPDT relay, connect terminal 30 to constant 12V (use an inline fuse holder) and tap your amp turn-on and 12V sockets off of terminal 87. The wire from the add-a-circuit goes to terminal 85 and ground terminal 86.

So it'd be safe to say that just tapping into the add-a-circuit directly wouldn't be a good idea? A relay looks like a safe solution though, never really knew the purpose of them before, now I do. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif Thanks!