Reddit mentions: The best car amplifier fuse holders

It's extremely easy to DIY. I'd strongly recommend visiting YouTube. Most customization shops will likely do it, but AFAIK it's not that common of a task due to how simple it really is to do. There's videos for pretty much any popular car model.

A screw driver, some zip ties and maybe a knife or pair of wire strippers is all you'll likely need to do it right.

In case anyone is curious here's what's involved:

1. Stick camera where you want it (likely behind rear view mirror as high as possible).
   
2. Tuck wire between headliner and roof of car, you can use a little tape if needed, in most cars it's not really needed if there's some tension. You're wiring towards normally towards the driver side A pillar in most cases since that's where the fuse box is, however in a few cars it's on the passenger side. Check your manual it will tell you. Leave a little slack for adjustments by the camera. Just a tiny bit of slack by the pillar.
   
3. When you get to the A pillar, there's normally some clips/screws that you need to remove and the plastic trim comes right off. It's made to easily come off. If your car has an curtain airbags they are here, so a little caution is needed. You can remove the neutral cable from the battery to fully disarm if you're really nervous but they aren't THAT sensitive, it's not like they inflate if you go over one of our many glorious potholes. Just don't punch the damn thing. For almost all cars there's a bunch of wires behind the airbag that go down into the dashboard. Use some zip ties and secure your new cable to those existing ones. The important thing here is to keep your new cable behind the airbag at all times, so you don't obstruct it. Just follow the existing cabling.
   
4. Tuck that cable down the hole at the bottom of the a pillar and feed it down to where the drivers. You may want/need to unclip some plastic down there by the foot well.
   
5. The ground wire can be secured to any metal part that touches the frame. There's always some screws you can remove one and use that to screw down the ground wire. Now you're half wired.
   
6. Now the positive goes into the fuse box. Since you almost certainly won't have spares, you'll need to tap something. No worries that's simple just a matter of what to tap. You can find a fuse tap for cheap on amazon or any auto parts store. Note there's different sizes. Your manual will tell you what you need or just ask at an auto parts store and they can look it up. Look in your manual for what is what, you want to tap something non-critical. Obvious reasons. It's normally a table of each fuse position and what they power. For example the radio. Something that turns off when the car is off, but works when your car is on. Pull the appropriate fuse, put the tap in, then put the fuse in the tap. Then crimp the wire from your dashcam to your tap.
   
   That's really it. All that is a detailed way of saying "thread the wire around your windshield to the fuse box then bolt the neutral to bare metal and put the positive in your fuse box tapping a non-critical fuse that's only energized when the car is on."

Have you wired... anything before? You'll need to be able to terminate wire to do it, but that's not too big a deal. There's also a bunch of different ways to go about it, depending on who you talk to. My preferred method goes something like this:

Acquire parts:

• 4 gauge copper stranded, jacketed wire of appropriate length to reach from starter to house battery, plus a little wiggle room, plus another section to go from house battery to frame.
  
  
• an in-line fuse holder to go right off the starter battery positive
  
  
• another fuse holder for the house battery, I like to use a triple-fuse holder, but you can just use another in-line like the one above.
  
  
• 100 amp fuses for both
  
  
• 4 gauge ring connectors/lugs.
  
  
• some sort of isolator. Basic-tier manual, a dual-battery manual switch (intermediate), or something more automatic, like a voltage sensitive relay.
  
  If you can't work out another good way to crimp the ends on, just pick up a crimp tool along with it.
  
  Plan:
  
  You need to create a circuit from the alternator to the house battery. Circuits are loops; in a DC circuit (as most are on a vehicle), the magic power fairies have to come from the power source via the positive terminal, through the thing they're powering, then return back to the negative terminal of the thing they came from. Most vehicles use the body and frame as the return path for the fairies. The devices' negative sides all connect to the body or frame, and so does the battery or batteries, so once they get to a device, they can always get back to where they came from, whether they came from the alternator (grounded through the engine block/bracket), starter battery, or house battery.
  
  Next, you need to consider where each component will live. You need to connect positive to positive from starter to house battery, with all the other doo-dads in between. The fuse holders should be very close to their respective batteries. Like, less than a foot. I lay my starter battery's fuse right on top of the battery, so anyone working on the van later can't miss it, and should know to consider the rest of that circuit when appropriate. My starter battery's fuse is mounted right next to the battery. The placement of the isolator depends on what kind it is. If it's a manual type, you'll need to access it from within the cabin; I like to put my house battery and a manual isolator pretty close behind the driver's seat, so I can operate the switch from there or from within the cabin. If you go with an automatic jobber like the VSR I linked, that doesn't need accessed again except for troubleshooting, so it's common for it to be mounted near the starter battery in the engine bay. Either way, the wire will go from starter battery positive, through a fuse, through the isolator or VSR, through the house battery's fuse, to the house battery positive.
  
  
  
  There's two types of connections to make with the linked items: "set screw" and "lug". The fuse holders I linked all use set screws, and everything else will use lugs. To make a lug connection, you strip back the wire jacket from the end of the wire just enough so the remaining copper strands fit into the sleeve (and only the sleeve) on the lug, then crimp it down. The lug then gets a bolt through it to make its connection. There is typically already a bolt on the starter battery terminal somewhere, and this is where it will go, though both batteries' terminals will vary in their format. You may need an extra doo-dad to make it right. For a set screw type connection, you strip back the wire jacket as before, back out the set screw, put the wire in its hole, then tighten it into place with the set screw.
  
  Installation:
  
  Snip off a foot of 4 Gauge wire, remove the fuse from the inline fuse holder, then set-screw the wire into one end. The other end of the wire gets a lug, and goes on the starter battery positive. From the other end of the fuse holder, route it to a VSR (if applicable; install its additional ground wire to one of its mounting screws, into the body), then on to the house battery location. Here, it will go through a manual isolator switch (if you don't choose the VSR), then through a fuse, and on to the house battery positive terminal. The negative terminal of the house battery gets connected to the van body or frame with a couple lugs on as short a wire as possible; a seat or seat belt hole is typically a good ground lug - just remove the bolt, add your lug with wire already crimped on, and reinstall the bolt.
  
  Once all connections are made, you can go back and insert your fuses. If you chose the dual-battery switch, it has 3 lugs on it: a "common" lug, battery A, and battery B. The wire coming from the starter battery goes to battery A, the wire going to your house battery goes to battery B lug, and the common lug is for your load (aka, your devices). The switch has 4 positions: "A","B","Both", and "off". You can set it up other ways, but in this configuration, the first two select which battery power is drawn from for the devices connected to the "common" lug, the "both" setting literally chooses both, which means it also is the setting for charging your house battery, and "off" ensures the devices get no power from either battery, and that the batteries aren't connected to one another.
  
  Manual isolator operation:
  
  With the engine running, turn the simple isolator "on", or the dual-battery switch to "both". This connects the batteries, which connects the alternator to the house battery. If the alternator can charge it, it will (see "Caveats" below). When you stop running the engine, and want to run devices without draining the starter battery, turn the simple isolator "off", or set the dual-battery switch to "B". If you go with a VSR, this happens automagically for you, and you can forget I typed this paragraph.
  
  Caveats:
  
  The house battery isn't as close to the alternator as the starter battery. This introduces resistance to it, which comes with voltage drop. The alternator has a voltage regulator in/on/near it that senses the voltage of the battery (or batteries) it's connected to, and if that voltage is lower than its setting, it will kick on, and start charging, typically at or above 13.8V, maybe 14.1. An idle, full battery will read closer to 13V. A 12V battery is actually dead if it gets down to 12V; anything running on 12V accepts all these voltages, and so these systems are considered to run on "12V nominal", which is a range including all these. Anyways, from the perspective of the alternator or house battery, there is less voltage present on the far end than from the near end, due to the voltage drop over distance in the wire. So, the house battery never sees full charging voltage from the alternator, and therefor may never fill all the way up. Measure voltage at the starter battery while the engine's on and alternator's charging, then measure it again at the house battery. The difference between these two is your voltage drop, which should be in the 1-3% range. More or less, this is how short of full you can get your house battery only charging from the alternator.
  
  If you choose a manual isolator, you will get the most charging output possible from your alternator, and you can throw the switch to "jump start" yourself if your starter battery should die, but you might forget to turn the switch one day, and accidentally drain your starter battery. I simply make checking the state of the switch part of my van start-up and shut-down routine, and have only had a problem once. If you instead go with an automatic isolator or VSR, you won't have to worry about this, but your charging rate will be limited by the rating of the device chosen, if its rating is below the alternator's rating.
  
  Your power distribution to your loads still needs additional fusing. If you use the dual-battery switch, most loads should come off the common lug, through a fuse, and on to the devices. If not, then connect them from the starter battery, through a fuse, and on to the devices. Many people install a fuse block with multiple fused circuits to go to various devices; it needs a fuse in its feed that is as large as all the other fuses combined.
  
  Wondering why I linked a triple-fuse holder? It's a neat sort of junction for the house battery's positive terminal, where everything connecting needs fused anyway, and these particular fuses can need to be quite large, though different sizes. 100A alternator charge, 50A+ load distribution, 30A+ solar charge, or the big ol' honkin inverter I tend to install on my builds.
  
  

>What's the danger of doing something like this?

Building on a pre-made unit with a low voltage output takes away so many worries. So assuming that the ATX PSU stays in good working order..

The biggest danger comes from the fact that the unit will happily pump 100 amps into the right kind of short. As the other commenter said, there may be some short-circuit protection, but there must be some range of loads into which it will deliver that maximum power. Whatever your project was supposed to be, it is now inside-out toaster oven.

1. Keep it powered off whenever you're not there watching it.
   
   ​
   
   >And is there a way to protect from shorting two different power lines?
   
   Assuming you don't actually need hundreds of amps, I would:
   
   
2. Disconnect all but one of each (e.g., red and yellow) of the power wires. Doesn't have to be permanent, just take the end out of the ATX connector, insulate it, and tie it back neatly. Keep at least as many ground lines.
   
3. Put an inline ("pigtail") automotive ATC/ATO fuse holder in each of the supply lines you want to use. Something like (no affiliate) 14 Gauge Fuse Holder ATC/ATO, 10 Packs in-Line Automotive Blade Fuse Holder with 50PCS Standard Car Fuses
   
   There are all kinds of thermistors, PTC switches, and other options for resettable circuit breakers worth looking into, but you'll never regret having an assortment of fuses handy.
   
   Now that you've got MOSFETs working in switching configuration, you might look into enhancing your supply with adjustable current limiting.
   
   - Marsh

Amps use the RCA wires for the sound signal so you just need an amp and a sub.

Like the other guy mentioned, the blue is just a 12v signal. When the head unit turns on it just sends 12 volts and the amp turns on.

You'll need a short amount same gauge wire as the red wire to ground the amp to the chassis. The electricity needs some way to get back to the battery. I bet if you look around under the carpet to the side you'll find the ground wire bolted somewhere to the metal under the carpet or along the side.

Like /u/cancerous_anus said, definitely check along the red power wire, probably under the hood, for a fuse. If not most definitely put one in. Get something like this. They use the old style glass fuse.

https://www.amazon.com/DS18-FHSANL1014DIG-ANL-Fuse-Holder/dp/B01GVHN78C/ref=mp_s_a_1_57?ie=UTF8&qid=1548901764&sr=8-57&pi=AC_SX236_SY340_FMwebp_QL65&keywords=anl%2Bfuse%2Bholder&dpPl=1&dpID=41YYnvsEOnL&ref=plSrch&th=1&psc=1 this one is pretty sweet

Thanks man after following ur advice, I found that the trailing edge did not give any voltage feedback but the side closest to the battery did give feedback. Running a continuity test I further found out the fuse failed. Whats interesting is that the fuse looks intact from just looking at it. The fuse is a AGU 80 amp 5AG80A
Saying that I have found two problems with my installation that were the likely causes of my issues. 1)I had left the rubber inside the terminal of one end on the fuse holder. There is now a black singe mark inside the terminal. 2) The fuse is a AGU 80 amp fuse, after doing some research I have found that the recommended fuse for 4 gauge wire is 125 Amps. I have went out and bought a new inline fuse holder with a ANL 150 amp fuse.

Thanks for the advice.

Yep, inline barrel fuse. Looks like this one

Tap a fuse - 1st fuse protects your vehicle, 2nd fuse slot protects your dash cam - allows you to tap into the fuse, and power your dash cam.

No splicing the factory harness... but it does require splicing into two of the wires that connect to the button. The connectors snap over two of the wires to the button (unless I can find a connector that matches the button connector).

Power comes via an add-a-fuse connector, the ground connection works on any screw / connection to the vehicle body, and the button wires are tapped via snap on T-Tap connectors.

An additional benefit is that only changes the startup state - the button still works to turn it on \ off if there's ever a situation where you wanted it on.

An overengineered car stereo fuse holder like this one

https://www.amazon.com/InstallGear-Gauge-Line-Fuse-Holder/dp/B01CT4ZJHS

looks like it:
https://www.amazon.com/Baomain-Glass-Holder-Screw-Radio/dp/B01M4R7W3S

I am assuming that the reason you want to hardwire the dashcam is because your cigarette lighter is live all the time, even when the ignition is off. If that is the only reason, you do not have to hardwire it, you can purchase a switched lighter adapter and keep the dashcam plugged in all the time and turn off the switch on the adapter when you leave the car.

I am just saying that because you have not indicated that you are interested in hardwiring because you want to use the dashcam in parking mode, and because you have said that you have no experience in car electronics.

However, if you want to go ahead with the hardwiring, I urge you to watch some videos on YouTube demonstrating how to hardwire. Here's one, e.g. https://www.youtube.com/watch?v=3I9FZL8btqc

As to the fuse to use in your car, I see that you have 3 fuses that are spare. You can use any one of those provided that it only becomes live when the car ignition is turned on. The only way you will know that is by testing it with a circuit tester.

So, along with the circuit tester you will need to buy a 'add a fuse' such as this https://www.amazon.com/HitCar-Vehicle-Circuit-Profile-Holder/dp/B00U61OO50/ref=sr_1_9?ie=UTF8&qid=1468810452&sr=8-9&keywords=Add+a+fuse

Make sure that the blades of the fuse are the same as what is in your car.

Be very careful when working in the fuse box that you don't short circuit anything. It could be bad news.

In your drawing, you want a fuse coming off the 12v DC converter on the red wire before you connect it to anything else. Ideally, you need to figure out how many amps your setup should draw and get a fuse rated for just slightly higher. Your linked power supply has an output of 10amps so no higher than that. Something like https://www.amazon.com/VOODOO-Gauge-Inline-Holder-Fuseholder/dp/B07CXK6MCR/


Also, what /u/SliceofLie said. I would have separate power supplies. One for the arduino and one for the lights. However, if you add the extra fuse the worst case is releasing some angry pixies from the arduino.

http://www.amazon.com/KnuKonceptz-Gauge-Line-Waterproof-Holder/dp/B00Y17SOC4/ref=sr_1_1?s=hi&ie=UTF8&qid=1457813448&sr=1-1&keywords=waterproof+anl+fuse+holder

you aren't getting much smaller than this i believe.

will this do? https://www.amazon.com/InstallGear-Gauge-Line-Fuse-Holder/dp/B01HDX3WAG/ref=sr_1_5?keywords=amp+fuse&qid=1564631642&s=gateway&sr=8-5

I have, here's my install: http://www.focusfanatics.com/forum/8943153-post48.html

My add-a-fuse: http://www.amazon.com/HitCar-Vehicle-Circuit-Profile-Holder/dp/B00U61OO50

Just put a similar setup in my small shed to run lights and a few other things. I put this between the battery and the items i was powering so i could add circuits as needed.

Ok so ill be ordering this one.

Could water have potentially gotten to the fuse and cause it to blow? I saw slightly exposed wire where the fuse connects to the wire via allen key that is now covered with electrical tape.

I'll show you my setup to see if it will work for you.

Dashcam - https://www.amazon.com/V1-Dashboard-Recorder-G-Sensor-Recording/dp/B00X528FNE/ref=sr_1_4?s=car&ie=UTF8&qid=1484000259&sr=1-4&keywords=dash+cam

add-a-fuse connected to an always hot fuse under the passenger side - https://www.amazon.com/HitCar-Vehicle-Circuit-Profile-Holder/dp/B00U61OO50/ref=sr_1_1?s=car&ie=UTF8&qid=1484000314&sr=1-1&keywords=add+a+fuse

12 volt to 5 volt adapter cable https://www.amazon.com/WheelWitness-Hardwire-Installation-Dashboard-Charger/dp/B00TGQ1Y3Q/ref=sr_1_3?s=car&ie=UTF8&qid=1484000362&sr=1-3&keywords=12+volt+to+5+volt+adapter

Run that to the dashcam, add a 64GB microSD and record at 720p.

You should get around 6 hours of footage before it erases the older one. You can spend a little more to get a dashcam that will support 128gb SD cards and get 12-14 hours out of it.

If you connect it to an always hot 12v fuse, you should have no problem keeping the dashcam running 24/7.

Note: In Texas, temp near the windshield can exceed 110 degrees so make you get a capacitor based dashcam if you live somewehre that gets really hot or really cold

No. Do not order and use a 150A fuse with that 4 gauge CCA wire. This is the fuse holder you should use.

https://www.amazon.com/dp/B00XYQWSG6/ref=twister_B00XYR9VE2?_encoding=UTF8&psc=1

Your previous fuse holder likely melted because either A) It was lying against something very hot under the hood B) You had a poor connection somewhere in the chain. Poor connections cause voltage drops. In any decent amplifier with a regulated power supply, when voltage drops, current increases to give you the same wattage out.