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Discussion Starter · #1 ·
Hi everyone.. Have had to jump my battery a couple times in the last week. Went to subaru dealer, they said no issues with battery health, starter, or alternator. which leads me to believe that there is a parasitic drain on the battery.... I read up on the subject and most resources are saying that while performing a draw test, for a standard car, above 0.05 amps (50mA) means there is a drain somewhere. However, some resources say that "modern luxury cars" can pull up to 0.1 amps (100 mA) normally.

Anyone have an insight on the normal amperage for a wrx?

I installed an aftermarket amplifer (a tiny one, only 45w x 4) which shouldnt be the issue at all, but I checked anyways by removing the power wire attached to the battery (for the amp) and the test yielded the same results.


Is 0.072 amps average okay for a WRX ???
 

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Honestly not sure that doesn’t seem out of the ordinary to me.

Did you alter any wiring for the amp install
 

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Discussion Starter · #4 ·
Yeah, I had to splice into the factory HU harness for audio and acc power. But other than that, nope. kept the original speaker wire. The 15amp 16ga power line is going to the battery, 16ga ground is on a bolt under the passenger seat.

An option that I thought of was installing an inline on/off toggle switch onto the power line from the battery. The only issue with that would be a possible popping sound when flipping the switch after the car is already on.
 

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The drain is likely in your modified wiring. I’m not an electrician so you are out of my expertise in finding where
 

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So for your amp, you have 1 wire attached to the battery AND another one spliced into the HU power wire? Did you detach both and check if draw is the same?
 

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Discussion Starter · #8 ·
The amp is spliced into the middle of the HU harness. specifically, it's connected to all of the audio wires (to amplify the signal to the speakers) and the blue/white ACC Power (which used to go to the stock amp, i think). The ACC wire only tells the aftermarket amp to turn on and off when the car is turned on and off. The amp then has two other 16ga wires with one going to the battery for actually powering the amp and the other going to a grounded bolt on the frame of the car.
 

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So how did you know what to connect that blue/white ACC wire to on your new amp?
And are your 100% sure the other end goes to the HU?
 

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Discussion Starter · #10 ·
The amp only has one ACC wire. and is also labelled as such in the product diagram/instructions sheet. So yes, i'm quite sure that it is the correct wire to connect to the HU. And also, yes I spliced the acc power from the rear of the HU. Though, i'm pretty sure the signal is sent from the HU to the stock amp, so my amp is now completely 'replacing' the stock amp.
 

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OK, another question: Are you sure that blue/white wire is blue and white or could it be light grey/white from the HU?
 

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Discussion Starter · #12 · (Edited)
I don't remember tbh. I just know that on a wiring diagram I found, it showed it as ACC. According to the amp manual (http://support.alpine-usa.com/products/documents/OM_KTP-445U.pdf)
"For the “Speaker Level Input System” setting, connecting the
Remote Turn-On Lead is not required due to the “REMOTE
SENSING” function of this product. However, the “REMOTE
SENSING” function may not work depending on the signal
source connected. In such a case, connect the Remote Turn-On
Lead to an incoming power supply wire (accessory power) in the
ACC position.
A Remote Turn-On Lead (Blue/White)
Connect this lead to the remote turn-on or power antenna
(positive trigger, (+) 12V only) lead of your head unit." so I either connected the remote turn-on (blue-white) to the HU ACC or the power antenna.

In the meantime, I did install two things.. an add-a-fuse on one of the empty slots in the main fuse box, which is now supplying the amp with power, and a toggle on-off switch in the dash on the same power wire. So now i can manually turn off the power going to the amp. Will be doing another multimeter test this afternoon.
 

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I was looking at my 15 schematics and couldn't find the wire colors you mentioned; that is why I was asking.

I am curious about mine now and will also try to remember to check mine tonight. Mine is stock.
 

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Discussion Starter · #14 ·
So I followed this guy's instructions for wiring.. he does a great job explaining this (https://youtu.be/2dCXRGp-nEc?t=780) wiring diagram starts at 13:00

So he has a different setup but that diagram he created is the source of my info for which signal to pull the remote-on from.
 
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