Dayum Bruce! Thanks for the education!

 

That was an interesting read.



I guess that if that negative battery terminal ever went bad / got corroded that we would have to go back to the dealer to get a new battery monitoring sensor. We would not be able to just put a generic ' universal " battery terminal end on the cable. I don't even want to think about how much they will cost.


So If one was to add a higher powered amplifier to a 2017+ Impreza, where should we hook the power to? I would usually run it directly off the positive terminal on the battery ( with it's own fuse ) but it almost sounds like this could cause the computer to not properly charge the battery ?

 

So If one was to add a higher powered amplifier to a 2017+ Impreza, where should we hook the power to? I would usually run it directly off the positive terminal on the battery ( with it's own fuse ) but it almost sounds like this could cause the computer to not properly charge the battery ?

An aftermarket amplifier being wired from scratch should be grounded as close to the amplifier as possible. If properly connected to the chassis, the ground connection will find it's way back to the negative terminal of the battery through the current sensor and everything should operate fine.

 

H*ll Bruce...you are like dealing with Google...is there anything that you don't know

:wink2:

 

H*ll Bruce...you are like dealing with Google...is there anything that you don't know :wink2:

Thanks for the feedback

I have been working with electronics since I was about 8 years old. I started with vacuum-tubes. I now work in the semiconductor industry for one of the largest and oldest corporations on the planet. As an Engineer, it is my job to research and be aware of these things. My company EXPECTS me to spend some of my time doing research. I write software for a living now.

For fun, I like to rebuild engines and work on other electro-mechanical devices. An automobile electrical system has come a LONG way in the past 10 years.

I do not know much about art nor gardening ... But, as they say, one does not know what one does not know.

 

That little box mounted to the battery is a CURRENT SENSOR. It also detects battery temperature. It feeds information regarding battery drain/charge to the computer. The computer uses this information to control the output of the alternator and idle speed. The main reason it is there is to improve MPG to meet Federal mandates.

It is also VERY important to understand that adding additional electrical loads (amplifiers, lighting, horn...etc) directly to the battery which bypass this sensor can result in discharged battery.

Here is some more details regarding this sensor ==> https://www.furukawa.co.jp/english/tukuru/pdf/bm-sensor_e044e.pdf

 

Yes I am wondering what the little box on the negative terminal if for

 

Are you asking about the tan slimy looking stuff? It's on my batteries negative terminal as well.

 

I thought he was talking about that little box and the wires leading from it.

 

To me that looks like lazy engineering, something that was added on.