Missing Fuses, and battery draining when cars off

[Jai Bunney]

I have just bought a new car battery 5 days ago and have not driven the car for 2 days.
Before i took it for a drive today I decided to look under the hood and noticed the battery was red, and it struggled to start.
I ended up taking it to the dealership i purchased it from and they said to charge it overnight on a battery charger and leave it and see if it drains again and they'll swap it for another one.
Instead i chose to disconnect the battery by the negative terminal over night and literally as i did that the green blob appeared and started to come back almost instantly...
Im hoping if i leave it disconnected overnight it'll stay green as a few days of it doing nothing shouldn't drain a new battery. Hopefully that will mean that something in my car is somehow still draining the battery when its turned off...
Would anyone have any idea if id be able to check certain fuses or what wires generally could be causing the battery drain? And how to use a multimeter to test either the fuses/box and wires to check? Or if there are any accessories or fuses connected to the heater that can be swapped to a spot that isn't connected to the battery when ignition is off, as i have a slight feeling it could be my a/c..🤔
And also when looking at the fuse box i noticed that there should be a fuse on the battery spot and if anyone knows what that means not having it and if its necessary to purchase one and the same with the missing fan fuse?
I don't think they are related to the draining battery but after looking at another Magna's fuse box which was a mirror to mine at the dealership today it had the missing fuse in its box where the two fans where and in the battery section too, so im assuming i should have fuses there too..
Im driving a Mitsubishi Magna VR TW Wagon 2005.

[Jai Bunney]

I have a photo of the fuse box and the fuses that are missing but not sure how to upload a photo here...

[leadfoot6]

Is the electrical system COMPLETELY standard, or have you installed stereos/speakers/accessories etc.?

[cooperplace]

Do you mean radiator fan or heater/AC fan? My TW wagon has only 2 of the former; has 3 of the latter.

[Jai Bunney]

I do have an installed headunit, but that's it. Everything else is stock..

[Jai Bunney]

Do you mean radiator fan or heater/AC fan? My TW wagon has only 2 of the former; has 3 of the latter.

I really wish i knew how to upload a photo to here.. but i think its either the radiator fan or the a/c fan, they are marked G and H. It's G that is missing a fuse, both at the top right of the bonnet fuse box.
And the 3 battery fuses down the bottom of the fuse box are all good it the battery fuse marked F that is missing? �� Thank you for your replies

[Jai Bunney]

Is the electrical system COMPLETELY standard, or have you installed stereos/speakers/accessories etc.?

I do feel like there is a fault in a ground wire somewhere though. As i use Bluetooth to the headunit to play music now, because when i use the AUX cable and something is plugged into the centre console a/c socket there is a white noise humm in the speakers that usually wasn't there.

[leadfoot6]

As is often the case, sound system modifications can be the cause of strange electrical problems.

For the record, my car's electrical system is COMPLETELY standard, and I have had no problems with it.

I have a "Bluetooth" enabled plug in(to the centre console socket) radio transmitter that allows me to use a USB stick library of music tracks that broadcasts to the standard headunit using the standard speakers.

https://www.ebay.com.au/p/Wireless-B...iABEgJgJPD_BwE

The sound output is nothing extraordinary, but just like the standard system, it is "good enough", but with the ability to play vastly more tracks than your average mp3 CD in-car library.

As part of "future proofing" my car, I had MitsFix install a brand new genuine alternator when the 380 transplant was carried out, even though the original 15 year old charging system was showing no signs of trouble.

[mcs_xi]

I do feel like there is a fault in a ground wire somewhere though. As i use Bluetooth to the headunit to play music now, because when i use the AUX cable and something is plugged into the centre console a/c socket there is a white noise humm in the speakers that usually wasn't there.

That is called a ground loop and it means something plugged into the audio system is earthed in two places. This will cause an annoying hum but won't drain the battery unless it's getting power at all times.

Since these cars are getting older now, a common fault is the alternator diodes fail. as the alternator is directly connected to the battery, the diode is a one-way circuit for the battery to be charged by the alternator. When this fails, it will allow the battery to simply drain away.

You can disconnect the 12mm bolted wire going to the alternator, and if the battery seems to last, then replace your alternator (alternator, voltage reg and diodes are one unit)

Mike

[cooperplace]

You probably don't have missing fuses. There are slots there that are unused in some cars.