Hardwiring Kit fuse options

alamsas

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Hi guys, I have a '19 WRX and attached is my fusebox map under the driver's side.

I understand I need piggyback fuses and so I bought two.. but I realized I could plug the yellow (ACC) wire in one of the vacant slots. The red (Battery) wire however, needs to be actually piggybacked with another fuse that is permanently running (the ones that are always on are the ones with the green dots).

So I have 2 questions.. My piggyback fuse is rated for 15A fyi.

- Can I/Do I still need to use the piggyback fuse for the ACC wire if I'm going to use an open slot? If I do use it, do I just put in two 5A fuses in there? I would like to do a clean install so I don't mind doing that rather than wrapping the wire on a single 5A fuse and plug it in there.

- It seems like the door lock would be the least important fuse I could piggyback my Battery wire on. My understanding is that I'll use the same 15A fuse on my piggyback along with a 5A fuse correct? But if the piggyback fuse is only rated 15A, does that mean it won't work? Or is the 15A only for the 2nd fuse slot you use for the dash?


Thanks!
 

DesertBike

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You're in luck. I just installed my A129 using the 3-wire hardwire kit so can answer your questions.

1) Yes, you still need a fuse (5A is what was included with my kit) on the piggyback line (lower slot, inline with the wire coming out), else you won't get any power out of the ACC slot. If you're using an open slot, there is no need to put a fuse in the upper slot of the piggyback holder.

2) Yes, you will re-use the original fuse (in the upper slot of the holder) if you want to tap power off the door lock circuit. 5A for the power going to the camera (lower slot).

You are essentially wiring the camera in parallel with whatever circuit you're tapping for power. If the camera goes nuts for some reason and tries to draw more than 5A, it will blow its fuse. Your door lock circuit will still work however as it is on an independent 15A fuse.

The other way round applies too - if somehow the door lock circuit blows its 15A fuse, you will still get power to the camera through its 5A fuse.

Hope this helps!
 

HonestReview

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Test Fuse Seater HTR (15A) for ACC (Yellow) - Ignition. I use this on my vehicle. You want to avoid fuses that use electrical systems or have electronics associated with it. Test this one, but it should be fine.

Do you have Powered Seats? By the look of the fuse box, the answer is "NO". Some suggestions for Red (Battery) might be:

Door Lock (15A)
12V Plug

Some of this process is trial and error. As connected systems are not always easily discovered so a fuse that looks benign ends up being linked to something else.

Using a Voltage Meter or LED Light Tester:

Yellow should only light up AFTER the ignition is started
Red should be hot even if the vehicle isn't started
Black = Ground
 

DesertBike

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Interested to know whether OP can get the fuse panel cover back on after installing the fuse taps/piggybacks.

I can't, so far. The piggybacks are too tall, and also there are no provisions in the cover for wires leaving sideways.

I'll have to modify the fuse cover. It has several storage slots molded in for spare ATC fuses, and a miniature fuse-puller tool. I think with some/all of those storage slots removed, there will be enough height with the cover closed to still have the piggybacks.

I'll likely have to cut slots for the wires too.

For now the fuse panel has clear tape over it, to make sure the piggybacks don't get knocked loose accidentally. Ugly, but effective. :)
 

Gooffeyguy

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Does the yellow wire need a fuse, it just senses voltage?

Sent from my SM-G930V using Tapatalk
 

HonestReview

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Interested to know whether OP can get the fuse panel cover back on after installing the fuse taps/piggybacks.

I can't, so far. The piggybacks are too tall, and also there are no provisions in the cover for wires leaving sideways.

I'll have to modify the fuse cover. It has several storage slots molded in for spare ATC fuses, and a miniature fuse-puller tool. I think with some/all of those storage slots removed, there will be enough height with the cover closed to still have the piggybacks.

I'll likely have to cut slots for the wires too.

For now the fuse panel has clear tape over it, to make sure the piggybacks don't get knocked loose accidentally. Ugly, but effective. :)
I took some scissors and cut the cover to allow for the wires.....Not the prettiest but about the best you'll get.
 

DesertBike

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Does the yellow wire need a fuse, it just senses voltage?

Sent from my SM-G930V using Tapatalk
Yes. You have to install a fuse, or the circuit won't be completed and the piggyback does nothing.
 

HonestReview

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Does the yellow wire need a fuse, it just senses voltage?

Sent from my SM-G930V using Tapatalk
Yes. If you are using fuse taps, the original fuse goes into the slot closest to the fuse box. The secondary fuse (use 5 amp) goes furthest away. The point of the 5AMP is to protect the camera.....So yes it needs one.
 
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