How to tap into your cars fuse box safely and cleanly 

The fuse diagram on the cover at the 1:30 minute mark also indicates which fuses are hot in which circuits--"Power Socket," "Mirror," and "Cigar Lighter" all have an "ACC" header, "Heater Mirror" is under the "IGN" header, and the "hot at all times" fuses have a "BAT" header. This is extremely useful information, and it would save you the step of having to determine which one is "hot with ignition relay energized," for example. One quick look, and you can likely take a remote turn-on signal from the "Mirror" fuse so that your amplifier or other unit will turn on when the key is in the ACC position. I wish my car had that diagram!! Just recently, I needed to find a true ignition-linked circuit in order to provide a 12v signal to a battery isolator relay. In other words, I had to find a 12v source that would only be energized when the key was in the "On" (and "Start") position but not energized in the ACC circuit. The purpose of this was to have a secondary battery automatically be connected to the starter battery whenever the ignition circuit was energized (so while starting the car, and when the car was running) but not have it connected to the starter battery when the car was not turned on, including when it was in accessory mode. This allows the secondary battery to handle all of the power supply to my audio equipment and aftermarket LEDs when the car is not running, so the starter battery doesn't have to provide power to any big load with the car off, but when the car is on both batteries are running in parallel and are taking charge from the alternator. I ended up adding a fuse tap to the "heated seat" circuit, which I was able to determine was only hot when the ignition coil was hot, by scouring through my car's workshop manual (2017 Ford Escape) but it took a long time to find it. So a simple diagram like the one Nissan includes on their fuse box cover can be invaluable if you're doing something like this. Pretty niche, but I can't be the only one. Just adding this information here in case someone else who is learning this stuff, like me, will find it useful. Good luck!

Dean, you never know who you're going to help or when. In all my years, I never knew that there were contacts on the top of the fuse where you could check with a meter! I always pulled them to check. Thank you for that one.

Awesome video! Breaks it down and explains it PERFECTLY, especially for someone who was previously clueless like myself. Thanks so much!

A lot of what you said I did not understand, but at the same time you gave the instructions in a way that anybody can follow them. Thanks! You've helped me a lot.

I do a lot of DIY electrical work on my vehicles, and i always tap into the main orange accessory wire in the ignition which is dangerous. Thanks to this video, I can now do it safely using the fuse box tap method. You learn from your mistakes, so far no fires

Watched sooo many videos on this and yours was the first that explained it well enough for someone who knew nothing.

"Load" and "Draw" work for you. Correct electrical terms are "Line" and "Load". Line would be your 12volt, non fused side. Load would be the accessory, fused side. As an electrician, we calculate "load" to determine the fuse size. No criticism intended. Thanks for making this video. It is very helpful and useful! Now, where can I find the ATMLP fuse taps?

Wow, you should get a grammy for your camera work, lighting, information etc. It is so disappointing to see great content on the web and the crappiest ways to deliver such content, I appreciate the quality of your video in every respect, thank you.

Good stuff, I also wasn't aware of the fact that it mattered which way you place your fuse tap load or draw side, thanks for the useful info.

This video has probably got to be the best and most informative video that i have seen in comparison to time, information and quality (meaning you just showed what was needed, nothing more and nothing less) Thank you for the information !

This was very helpful. I didn’t know about the "load side" nor did I know that one fuse on a tap should be less than the other. Thanks so much! Glad I watched this, first.

Oh man, you are a star, I've been looking everywhere regarding what is the load side of one of those fuse holders!!!! Thank you sooooooooooooooooooo much!

Man, I thought i was good with car electricals until i watched your video. Your video is very educative and well presented too. Keep it up!!!

To help make sure you use those, "add a circuit" fuses it helps to find which way it needs to go by leaving the lower fuse out(only have the upper fuse installed) & checking for voltage though the added wire! This way you know you have it installed correctly where each circuit is isolated on its own fuse & only after you do see the voltage you install the lower fuse!

Bro you’ve saved the day on so many levels for me. I appreciate this so much thank you!!

Hey thank you for this I never knew these existed I always just ran a wire around the fuse and I always thought that looked sloppy. Now it’s nice and cleanly done thank you. I added two charger ports on the back of my armrest for my rear passengers so I don’t have to figure it out from the front plugs

Another way to make sure you have it connected correctly. Install the fuse that was removed from the fuse block and plug it into the fuse tap where it belongs. Connect the tap into the fuse block. Connect the red lead to your meter and ground the black lead from the meter. Turn on the key if connected to an accessory circuit. If you have power without the secondary fuse installed just reverse the tap. It should have no power until the secondary fuse is connected.

Good video, when i was young and inexperienced installing I did not know fuses had load and draw sides so I caught my 94 nissan on fire. While trying to install a small amplifier. thankfully I was able to rip the wire away before it was too bad. I'm now showing my son how to do things right and your video explained it right on the money. Thanks, B

You're an excellent instructor! Thank you for this exceptionally well-made video.

EXCELLENT video! You answered all of my questions regarding tapping into fuses AND MORE... These are the kind of informational videos that make youtube great... Thanks brother!

Very useful video. I never knew about the load and draw side of fuses. I assumed you could put them in either way. Thanks!

“Line” is the unfused supply to the power in leg of a fuse - It’s the power line into the fuse. “Load” is the electrical load placed on the fuse It supplies the electrical load connected to the fusible link / aka fuse Draw (current draw) refers to the current drawn from a circuit by a given load. Vary the load and you change the draw. The function of the fuse/ fusible link is to limit current drawn to a level that guage (cross sectional thickness) of wire can carry without getting so hot that it causes the insulation to melt or catch fire. A thicker copper wire can carry a larger current draw and supply a larger electrical power load. Nice video though. 🙏

Awesome video. Wish more people presented tutorials as perfectly as you did here. Great job, guys!

Great video Linear, explains why, to the point, we can see the work, and no side bar rambling. Video is very useful to me. However, this video is for radios and I am installing fog lights with a relay. I am going to use what I learned from watching this to try to make it where the fog lights do not work unless the key is in the ignition. Now I need to find out how to use an empty relay spot and how to connect the relay.

Is this adult Morty? In all seriousness, you are a lifesaver.

if someone needs to know how to make proper tutorials and explainations, they should learn from you sir! you sir are the best! love to watch all of your videos!

Installing my first boss radio, this is the info i been surching for weeks lol

Great job and taking the time to do the video. The only thing I would suggest is to correct the terminology so people aren't confused. The "LOAD" is the device that you are protecting with the fuse that "DRAWS" power. The "SOURCE" is the power "SUPPLY" that provides the energy to the circuit. For ease if conversation the following terms can be interchangeable. SOURCE=SUPPLY=POWER=Battery LOAD=DRAW=DEVICE=CIRCUIT=Amplifier or dash camera

Very informative video! Wish I would’ve seen it yesterday before I installed my halo headlights on the Wrangler 😎 I was searching today to see if the tap needed 2 fuses and you answered my question! Thank you.

Love their vids! Great installers and teachers! I hope they make millions and one day I would like shake their hands.

Note that the little contacts on top of the fuse will both show power (unless the fuse is blown), because they have continuity through the fuse element. To find the hot side you have to remove the fuse and test the plugs directly. Also, I can't think of a reason the bottom fuse in the tap would need to have a higher relative rating, unless you're inserting it backwards and making current flow through both fuses to reach the lead. Inserted the right way, each fuse is dedicated for its own circuit and should be rated independently.

Nice production and helpful instruction. At first I didn't like the music in the background. But within about 15 seconds I actually stared to like it. Great job, thanks for the clear info.

Wow I thought I knew how to do this, I guess I've been lucky in the past I didn't burn anything up, the load and draw info is invaluable. Thank you for a short consise video, the music could go though, your good enough without it.

Very well done video......most informative......I am in the process of checking some Auto Electricians work that I paid for and found some errors that have forced me to check all his work. This video confirms my suspicions. Many thanks .....

Very helpful. Clear, concise and to the point. Fantastic video!

Hello five star stereo I want to thank You guys for the great videos . My old car had no stereo or wires I could use . Thanks to your videos I was able to locate a ground a constant and did the fuse box adapter for ignition power and now I am jamming thanks. Hey Fernando Puro Pinche Parri!!

Wow love how you guys do everything with all details

Wow. I was about to snap. I jus bought a used challenger rt and decided to throw a better stereo in it. I’ve installed more aftermarket stereos than I can remember but never have a run into this. I start wiring my harness and the dodge harness has no 12v switched wire. At first I thought it was a mistake made by the factory. Nope apparently stock stereos in newer cars just run on hopes n dreams. Anyway I was about to give up hope and then I found this. Thank you so much. I hope you still actively make videos. I’m gonna follow for sure. Thanks again

Line side is from your power source, load side goes to your accessory (off road lights, amplifier, etc)

Good stuff, I also wasn't aware of the fact that it mattered which way you place your fuse tap load or draw side, thanks for the useful info. thanks again.

Learned something new today!! Thanks

Well done just like the first two guys I didn't know either I learn something very valuable I'm going to put in a backup camera I'm glad I watch you guys first thank you very very much

One additional item that I would like to know. Do the adapters fit so you can replace the Fuse box covers properly, with the additional height of the adapters, may or may not clear the cover? Many different fuse boxes with different vehicles. So maybe you end up creating a slot/hole in the cover? Pigtail also needs to be fished out of the box somehow? Nice video and thanks.

First video that accurately and clearly explains this stuff. Nice video!

Awesome you made it really clear to understand 👏🏻 thanks for making this video. Youre the best👌🏻

Thank you this is very helpful to know before I try to hard wire a dash cam to my car. Like the comment below I had no idea there was a load/draw side, I'm really glad you explained that part! Also the bit showing how to test with a volt meter, other videos say to do that but they don't show how to actually do it. Not everyone is good with electronics, thanks for showing this part!

and I have learned something new. Useful, thank you

Great advice all around. I acually was just looking up how to run a second fuse box and i gain so much from watching this video. I now have a better idea on how i want to run a few extra wires and circuits i need to install in my project honda.

6:55 fuse doesn't always have to be lower size, it can be the same size

Thank you!! I had an auto vox dash cam installed and it recorded a crash involving my vehicle. I had to troubleshoot because i had bought a new model of the same vehicle. Whole new fuse type and everything. You video helped out alot with the load and which side go where. Much appreciated.

very well explained.

Forgot to mention your video really did help me, and you did a great job. Thanks

This is GOLD! THANK YOU!!!

Awesome! I was able to hook up LED Halos on my ‘98 Tacoma after watching this.

I love that you literally cant drive that car in your garage without scraping the bottom.

Thank you for making this process dummy proof! Did it all by myself and works great! :D

8:50 Thanks Fernando for this useful tutorial! :-)

great informative video... clear and concise. I don't understand why people would put a thumbs down. Some people are just negative or jealous

This sure beats splicing into cigarette lighter wiring. I added a Volt meter using a tap and it works great.

Really nice explainer. Thanks for sharing the details of load/draw orientation as well as those little metal jobbies that hook onto the fuse. Didn't know about any of that!

Are taps and fuses labeled load and draw? How am I supposed to know which side is which?

This video was absolutely amazing buddy thx a bunch...my Mercedes ECU is not sending the signal for my cooling fan to turn on so instead of forking out 2k for a ECU going to buy a thermostatic fan switch and use that..and I need a ground ,constant power and ignition power to it and now I know how to wire the ignition wire safely and cleanly..thx man

if your tapping into an open spot (unused spot) would you need to put the primary fuse in or just the secondary fuse for the new circuit. I'm guessing only the secondary? If im wrong how would you determine what amp fuse is needed for the primary.

Thanks man, solved my problem at 4:06 I was installing power seat on my mk2 santa fe, seat worked when connected straight from battery, but when I plugged into fuse box it didnt work all problem was that I needed to flip fuse tap and it works 👌

load and draw are same thing. you have a feed "hot all time" and a load or draw side.

Thank you for all the great videos. I can’t tell you how much they help me with my first total sound system upgrade.

why are you calling the side that leads to the battery "load" ? One of the few things I remember from my degree as an electrical engineer is that "load" means the path heading towards the device that is using the electricity, not the source of the electricity electronics.stackexchange.com/questions/95874/when-people-talk-about-a-device-drawing-current-what-do-they-mean-why-do-dev

Really helpful cause I was trying to look ways to help me instal my light kit correctly and also not harm myself or my car in the process. Thanks bro

Still don’t get which way round the fuse has to go in the fuse box

Great content, simple explanation, this made sense to a Doctor.

not gonna lie, when I was in high school I used to do the wrap thing around the fuse then cram it back in..... I'm an adult now lol, but thanks for the tap info

Pointing to the load / draw side on a FUSE instead of where the FUSE PLUGS IN, confused me, I'm often pretty dim. You could say power source or to battery side etc., for dummies like me. After I figured that out it is an excellent vid. Thank you,

Not exactly related to the topic but... I'd be a bit worried about a shop that grounds a un-modded Infinity just driving it in....

Best walkthrough for this I've found very detailed and clear explanation. Thanks very much just did some footwell lighting my first "mod" love it cheers man

4:56 What are "little guys" actual name?

Oh yes! This "nice", as Fernando says, video of yours is really very helpfull, the very thing that i wanted to learn. Thank you very much. 💕

0:02 under car damage this is why i avoid garages like this

Thank you Bro.. and I love your background music.. It's so relaxing❤

nice vid very helpful

Thanks for the info, really appreciate the explanation and how to test the fuse plug before attaching any fuse taps. I never knew it had to be plugged in a certain orientation.

Where can I find the brass fuse tabs that you showed as an alternative to the add a circuit? I tried looking on Amazon but I'm not quite sure the exact verbiage to search for.

Very detailed video! Good thing I saw this, since most DIY videos do not explain that concept.

I'd be absolutely delighted if someone would show me how to put the lid back on the fuse box after fitting a fuse tap. Go on . . . do it, I dare you.

Awesome video. It was just the right one I needed to set up some lights in my truck.

Why do people add MUSIC to their videos making the SPEAKER HARD TO HEAR???? Oh My God it is EXCRUICATING trying to listen to the speaker with the MUSIC....

My brain hurt there , for a second lol. Put the lower value fuse on the load side ( as he pops in a 25 w fuse LoL ) Ya crack me Dean . Thank you for explaining it clearly 💪

Informative video, but the background music too loud for my sensitive ears

Master piece of explanation....Keep going. You have a great talent....

Way to bottom out the car pulling it into the shop LOL.

Very helpful and decent vid! Thanks. Proceeding w annoying Chrysler Sebring 01 pow wind issue, and God Bless America and you no-sleep hard-core types!!

had no clue how they worked . so just stayed away from them . thanks

Made this project easier to understand. I found out the only problem was my meter wasn’t on a good ground so I didn’t get a reading. Thanks.

@6:50 you put a 10 amp fuse in low side. then you said the load side had to be lower and you put a 25 amp in. im confused. Sorry just asking!

OMG I was dealing with all these issue today. Found out the hard way my car take ATM LP. Then I was told it didn't matter what fuse went in each hole. Also my car manual doesn't have layout of my fuse box and it's a 2018 Nisssn. I even went to a Auto store and told them that the top lights up in the bottom doesn't they act like I was crazy I was totally confused . Totally frustrating day. But after finding this video tomorrow will be a better day. Thank you.

Great video. Tks for showing the different types of fuses and taps.

I didn't even know this was a thing until my brother (also a car audio tech) sent me this video. I'm installing front and rear cams to my new deck and was worried about how to power them. Answer found. Thanks!

Thank you Sir. Your information is critical to what I needed . God bless you

. Seriously great video, helped me understand alot, not in the least hot side and cold side. makes perfect sense now.

5 stars to you!! Great finally got a job done been meaning to, and all in 1 video! Thankyou!!!!

I am glad to know of these adapters now, thank you. But fyi its line side and load side. Line side is always your hot side and load is what ever side something is pulling a load on it, im sure your like me and would like to know.