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USB accessory plug and a fuse tap!


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03frontier
User

Dec 3, 2021, 1:01 PM

Post #1 of 13 (759 views)
USB accessory plug and a fuse tap! Sign In

Hey there -

I had a great experience 1st time around (see my first thread titled "12V truck bed accessory sockets"), so hoping for a repeat performance with all your expertise.

My old truck (2003 Nissan Frontier) finally bit the dust, so it had to get replaced. Kinda miss it, despite the constant headaches it gave us:

RIP! lol



Now we have a 2015 Toyota Tacoma. 4L V6, 81k miles.

Wanting a more "factory" appearance inside, I prefer to keep visible accessory wiring to a minimum. To keep my phone charged while driving with GPS, I mounted it to the a-pillar with a Ram mount and routed the cable through the a-pillar, then behind the dash down to the fuse panel.

I intend on using an aftermarket usb accessory outlet, connecting that to a fuse tap and then connecting the fuse tap into the fuse panel. (I was trying to upload pictures, but the built-in image hosting service here wasn't accepting my jpg files.. wth?)

Now, my question: the fuse tap I bought has two slots. What size fuses go into those slots, that won't cause a fire or blow up my iphone?

Thanks for your advice!


(This post was edited by 03frontier on Dec 10, 2021, 10:44 AM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 3, 2021, 3:01 PM

Post #2 of 13 (756 views)
Re: USB accessory plug and a fuse tap! Sign In

The fuse holder is universal. The fuse size is determined by the current draw of the accessories it's going to feed. If you are talking about a GPS and phone charger on the same circuit, then 10A should be more than enough. Never use more fuse than minimum needed to supply the circuit under normal conditions. The fuse is there to blow if anything overloads the circuit.

I will report the issues with image upload.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Dec 3, 2021, 3:04 PM)


03frontier
User

Dec 3, 2021, 5:01 PM

Post #3 of 13 (748 views)
Re: USB accessory plug and a fuse tap! Sign In

note taken, and thanks for helping to troubleshoot the image hosting issue.

also, forgot to ask, does it matter which slot i pick? ideally, i'd like one that's always hot, regardless of ignition position. cuz i mean, how much can an iphone draw from the giant 20-30lb car battery, anyway? or is that a bad idea?

i have a multimeter. should i use that to figure out which slots are hot, and when? for the purpose of keeping my iphone juiced up, how much voltage should i be looking out for? or will they all read as approx. 12V?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 3, 2021, 5:12 PM

Post #4 of 13 (743 views)
Re: USB accessory plug and a fuse tap! Sign In

Don't you have an accessory socket or lighter?

You shouldn't be cutting into a fuse box. You can't piggy back off another fuse.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



03frontier
User

Dec 10, 2021, 10:26 AM

Post #5 of 13 (677 views)
Re: USB accessory plug and a fuse tap! Sign In

it's been a sh**show since last week on my end; but it's time to re-ignite this convo!

looks like the image hosting issue was resolved! these are the fuse taps i got; i'm sure you already knew what i was talking about:



and as for the accessory usb port:



the fuse tap has two slots for fuses. so i'm not cutting into the fuse box; just trying to utilize some unused slots already built into it.



my understanding is that you're supposed to use a bigger fuse (possibly 10A?) for the main slot, and then a smaller (maybe 5A? or 3A?) for the secondary that will go out to the accessory usb pictured above.

is that correct? or am i better off tapping into the wires for the cigarette lighter or usb port coming out of the dash? i'd much rather use what i've got; if i were to go with any other method i'd have to make it out to the auto parts store that rarely seems to have what i'm looking for in the 1st place.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 10, 2021, 10:52 AM

Post #6 of 13 (673 views)
Re: USB accessory plug and a fuse tap! Sign In


Quote
the fuse tap has two slots for fuses. so i'm not cutting into the fuse box; just trying to utilize some unused slots already built into it.


If you are utilizing an empty slot, that won't hurt anything but don't be shocked if there are no contacts in the slot. They may not wire slots that aren't being utilized.

You only need one fuse per circuit.

What you are describing is where a 10A fuse operates something that uses 5A max and then you add a circuit to that fuse that uses the other 5A so that additional circuit would be fused at 5A by itself and not 10A



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Dec 10, 2021, 10:53 AM)


03frontier
User

Dec 10, 2021, 11:28 AM

Post #7 of 13 (667 views)
Re: USB accessory plug and a fuse tap! Sign In


In Reply To
What you are describing is where a 10A fuse operates something that uses 5A max and then you add a circuit to that fuse that uses the other 5A so that additional circuit would be fused at 5A by itself and not 10A


i kinda figured i might've bought the wrong kind of tap; it dawned on me after i submitted my last post.

so, for the purpose of this little project, what i really needed was a fuse panel tap, and not the fuse tap i bought since i'm not trying to run the accessory usb off an existing circuit?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 10, 2021, 11:35 AM

Post #8 of 13 (663 views)
Re: USB accessory plug and a fuse tap! Sign In

I've never used these things so I really don't know what they are designed to do.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
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Dec 10, 2021, 1:08 PM

Post #9 of 13 (653 views)
Re: USB accessory plug and a fuse tap! Sign In

No doubt already said here or other thread. Don't use more fuses, added up than the slot you use was intended for.

Those tap things are apparently for one hot wire yet two slots in each? Why would they? I really don't know unless you want two 5s to make a 10a if it was.

Also - Have to plead IDK cars/trucks that still come with real cigar (used to be called that) are to dead short a heating element were fused high. For power ports hope or check OE is enough for what you are charging or doing with it.

IDK what your phone requires but are charged by OE ports all the time may be slower?

AS HT said those empty spots probably have no contacts in them were just using that panel for multiple vehicles that might have had tons of other things. Don't mess with it.

That if you want to run Niagara Falls backwards for power get a roof top generator - just kind of kidding.

Measure twice, cut once applies to lots of things this doubly included,

Tom



03frontier
User

Dec 15, 2021, 10:10 AM

Post #10 of 13 (599 views)
Re: USB accessory plug and a fuse tap! Sign In

Thanks for the input, Gents!

Tom - I just now saw your post. However, this past weekend I went ahead and rolled the dice; used my multimeter and confirmed that yes, a lot of those empty slots were just that. They didn't have any kind of connection running in them, EXCEPT FOR ONE.

With the ignition in the accessory position I found that the bottom contact did indeed have 11-12v running through it. Went ahead and plugged in my fuse tap, no sparks. Plugged in a couple 3A fuses into the tap, still no ill effects.

At this point my confidence was growing (heh), and I went ahead and connected the red wire on the accessory usb to the tap, found a nearby ground for the black wire and held by breath as I plugged in my iphone 13 pro.

Success! It was charging. As a guy with very, VERY limited knowledge/experience on car wiring, I felt this was a huge victory and pat myself on the back. Up to this day, car runs fine (at least it seems like it; no changes detected) and no fires.

I think it's safe to assume what I've done is safe... hope I didn't just jinx myself.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 15, 2021, 11:07 AM

Post #11 of 13 (593 views)
Re: USB accessory plug and a fuse tap! Sign In

If all you are doing is charging your phone, you'll be fine. Just don't overload the circuit with things that draw more current. That 3 amp fuse would blow if you did anyway.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Dec 15, 2021, 2:40 PM

Post #12 of 13 (580 views)
Re: USB accessory plug and a fuse tap! Sign In

I may have suggested this before if not practical for you then don't.
WHY not go right from the truck's battery - fuse it there not exceeding rating of wire used. Find a harmless spot to snake two wires thru firewall and LEAVE THE FUSEBOX FOR THE REST OF THE TRUCK OUT OF IT?
Just look some items (vehicles in general) have a large rubber grommet to pass thru get high rated wire (choose well) and re-fuse it for what you want to do.


NO it isn't going to run 110v AC at high wattage you are limited to quick high use then off. Cell phones, even laptops don't use squat it's compressors, other assorted things you are stressing out the truck's alternator or see where this truck would put a second battery and leave it totally out of the scene?


You can, I have and do all the time! For now just jumper boxes are NOT part of where or what they are in run pumps, AC for drills and crap anywhere I want. I tried and can about light up my whole shop now with one on the workbench!


It's your party this stuff is that easy LEAVE THE VEHICLE OUT OF IT. Done deal just like that. It isn't going to blow up your devices if you don't short something with that device and just think it out.


Problem solved - again, leave the vehicles out of this venture I do all the time and have for ages as NOT part of the vehicle at all,


Tom



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Dec 15, 2021, 3:27 PM

Post #13 of 13 (573 views)
Re: USB accessory plug and a fuse tap! Sign In

You're fine with the way you did it. Project complete.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.







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