Add a Fuse/Circuit

Ok, first off I am a novice when it comes to electrical mods. This weekend I installed a Pioneer 3200BT complete with bypass switch and steering wheel controls. This was the main part of my project but I would also like to hardwire my GPS and Radar Detector in order to clean up the inside of my truck. I have aftermarket hardwire kits for each, but I am a little unsure about safe power sources. I have researched the Add a Fuse (fuse tap) a little which seems to be the easiest and most efficient route to go. I have a few of questions though.

1. Can I wire both kits to a single fuse tap? Or, will this cause an overload?
2. If not, is it advisable to use 2 separate fuse taps on the same fuse box?
3. If so, what size fuse would one recommend?

Thanks for any information, and feel free to provide as much detail on the pros/cons of these as you like!

 

1. I'm not a wiring expert, but I would not do this myself.

2. This I would do, and have done. You should have plenty of empty fuse slots to choose from. The trick is finding the ones that work with the ignition on only. But that also depends on how YOU want your setup to work. I hard wired my radar detector and Sirius radio so the power source is off when the ignition is off, that way I don't have to turn each device on or off individually.

3. Each device has it's own electrical load, so you should check each one and use the size fuse that is needed for each. In this instance, bigger is not always better.

 

Thanks for the input! It appears that this fuse tap accesses one of the empty slots you are talking about, so if you didn't use one of these how exactly to you utilize the empty slot?

 

I would like to tap-in a circuit for my future bed lights

The lights will draw approx 9.16 amp.

From the above picture, I see that it would be ok for me to tap into the GREEN *TAIL* unused circuit. Is that right?

 

You mean only active when tail lights are on? ? ?

Well this is exactly what I want if this is the case because as I know myself, I'll forget the lights on if I don't do this

 

Ok it's perfect then. No auto-off but there is still less chances for me to forget the lights on with this parttern. Also, I don't have to have the keys in the ignition, I just have to turn the parking lights on, so that's perfect.

There is just one thing though, I went to my local auto store (canadian tire in canada) and they didn't have the mini fuse add a circuit, only the bigger model fuse. Anyone in canada knows who other than Canadian Tire hold the add a circuit?

I even went to a local electrical/electronic store and they don't have them.

 

Just do you know you can also piggyback those add a fuses.

 

^ i meant "just so you know". Stupid phone wont let me edit

 

Far to be an expert in electricity. What is that piggyback thing? Is it a method or just another type of add-a-fuse.
And llol yeah, Im also on the phone...

 

I'm in Montreal and I've been trying to find some all day. I just found a Canadian company that makes it.

http://www.picocanada.com/en/products/fuses_atm_accessories_981.php


To find where to buy them check that list and contact the sales agent closes to you. I'm gonna send emails to the ones listed for Quebec and try to get a few of them for myself.

http://www.picocanada.com/en/salesagents.php

 

I finally found the add-a-circuit at auto part stores here in st-jerome area. NAPA, BENSON, wathever all had them, but wanted to charge me between 30 and 40$!!!!!!!!!!!!!!!!!!! I finnally got it from an autopart store with no packaging and no included fuses for 23$ with tax. Best I could get. Canadian tire should have them, but went to 2 of them and no one had the mini-fuse model.

This shit costs 3$ on the web ... I was pretty amazed at how much profit they make on this item.

 

I haven't gone there to check yet but if they do it's not on their web site (or they're called differently) and a few members here have said that they only have them for ATO fuses, not ATM.

 

thanks for the information, i just installed one and it works awesome

 

For anyone looking for a mini add-a-circuit in Canada... The larger Canadian Tire stores have them - stk # 020-1615-4

 

I've got a question regarding the add-a-fuse and apologize if this is long winded as I have fairly limited electrical knowledge.....

Slot #2 (or "b") is the fuse for the accessory, and slot #1 (or "a") is the original size fuse for the original slot. Instructions for the add-a-fuse tell you to put the fuse you require (in my case - 2A) in slot #2 and plug it into the fuse panel to make sure it works - IF IT DOES'NT, YOU NEED TO ROTATE THE ADD-A-FUSE. This is telling me that there is a diode or something which is allowing current to flow only one way.

Here's my question - With a fuse in slot #2 ONLY, the add-fuse must be installed correctly for it to work.
With a fuse in both slots #1 & #2, there is juice to both slots no matter which way the AAF is installed.
How is this possible and why does having a fuse in slot #1 allow juice to flow to slot #2??

If it's plugged in INCORRECTLY and the fuse in slot #1 burns, there will suddenly be no power to the fuse in slot #2.
If it's plugged in CORRECTLY and fuse #1 burns, then fuse #2 will still have juice.

I guess the question is this: What kind of problems or damage would result by plugging the AAF in incorrectly if anything??

 

I believe the way the Add-a-fuse works is this:
You have a power input side, power goes to the supply side of slot 1 and the supply side of slot 2. From there, power goes across slot one and back to the fuse panel to power whatever it's intended to power. In slot 2, power goes across the fuse and out to your new accessory. This means there is a solid connection between the 2 supply sides of both slots and there is a broken connection between the output sides (one goes back to the fuse panel, one goes to your accessory). When you install the AAF backwards, power must travel across the slot one fuse, then it splits, part of the power going to the fuse panel to power whatever it's supposed to, the other part going through slot 2 and to whatever you added. This means the slot 1 fuse is acting as the fuse for both circuits which means if slot 1 burns out, slot 2 will no longer get power.

If you plug the AAF in incorrectly, that just means the slot 1 fuse is carrying the load for both circuits. Worst case, you blow out the slot 1 fuse.

 

So in this scenario, slot #2 is nothing but a conduit - not a fuse - and slot #1 is the fuse??

 

It depends, if the fuse in slot 2 is smaller than the fuse in slot 1, then it will still act as a fuse. In your case if a 10A fuse is in slot 1, a 2A fuse in slot 2 will still downstep the power it will allow to pass. It would still be possible to blow the 2A fuse in slot 2 without blowing the 10A in slot 1.

If you have the opposite, a 2A in slot 1 and a 10A in slot 2, then it is simply a conduit. There's no way you'd ever blow the slot 2 fuse because the smaller, slot 1 fuse would blow first, cutting the power.

 

Here's why I'm asking:

I'm actually using a blank spot under my dash. The problem is that it's located in the top row of the fuse panel, and to install the AAF correctly, the wire must be on the top side, which means I'm making a tight bend on the AAF wire to fit in this spot. I don't like bending it this tight, but want to keep this in a blank location, and this is the only blank that has power (thanks Toyota).

Here's what I'm thinking:
Stay in this blank location, but put two 2A fuses in the AAF and rotate it so the wire is located on the bottom and no longer bent. This way I'm still fused for 2A and if either of them ever burns, it will be the weaker of the two. By staying in this blank location, the only thing on the circuit is my AAF and I don't care that fuse #1 is covering both slots on the AAF.

Is my logic pretty sound??

 

I see what you're saying. Slot 1 doesn't actually power anything, it's just letting power through for the accessory added in slot 2, right?

If that's the case, I don't think there's an issue with that, at least none that come to mind.

If you want to get fancy, you could always run your accessory to the back side of the fuse panel and just stick a fuse in the blank spot for power. Very clean, no AAF required, just means tearing apart the dash...