[Donutninja]

Hi everyone. I've recently purchased a 2006 325i E90 here in Australia. I also purchased a Sony XAV-AX3200 to upgrade the head unit and provide extra functionality as well as improve the look of the interior.

I've done a lot of research and testing on the car on this forum and it has helped a lot. I'm about 95% of the way there concerning installation. Everything works EXCEPT the head unit remains on forever (it doesn't turn off even with ignition off and key is out, including when locking the car).

I didn't use a plug and play harnesses like everyone else as I didn't want to pay around $200 extra for harnesses so I purchased an eBay wiring harness for the car. Everything works but I'm afraid I may have the red and yellow wires connected incorrectly, causing my head unit to remain on at all times.

My set up is as follows:
eBay wiring harness


Sony supplied wiring harness (power supply leads)


I cut and soldered the wires together using the pin guide on https://pinoutguide.com/Car-Stereo-A...t_pinout.shtml for reference.

From the Sony wiring harness I connected:
-ground to pin 12 (GND)
-Rem out to pin 13 (RAD_ON)
-Illumination to pin 14 (KL58G - Backlight)
-Red (Acc) to pin 15 (KL30 - BATT +12V)
-Yellow (Battery) - to constant fuse box

Is this correct? The only thing I can think of this that I am connecting the yellow wire to the incorrect constant voltage fuse. However, after a bit more reading my other concern is that as per https://philipmcgaw.com/in-automotiv...ng-what-is-kl/ it says "KL30 is battery positive, there will be ’12 VDC’ on this at all times".

Can anyone help me sort this issue out? I would like for the head unit to turn on when ignition is in ACC position and to actually turn off when the car is off and key is out.

Happy to provide more detail or clarify if the above doesn't make sense.

[ctuna]

I didn't catch where you said which of the three basic sound systems you started out with.

http://www.e90post.com/forums/showth...ight=head+unit

[Donutninja]

Thanks for the link ctuna but it doesn't answer my question. I've been referred to that page countless times during my research and I've read it a few times. The only thing I can think of is to wire the red (acc) wire to the cigarette +ve wire (as per your link) and not directly into pin 15 as I have done.

Any thoughts on that?

Edit: I have the HiFi system (non Logic7)

[ctuna]

In the Technic harness for Hi Fi does not do anything at the Head Unit . The 12 Volt line used to power the Hi Fi amp is used
as a switching signal through a relay as a turn on signal . The Hi Fi harness from technic is only a plug to break
out the amp plug signals at the amp . Direct aftermarket
power wires with a fuse are used to connect aftermarket amplifiers to the power terminals on the amp .

The Factory Head Unit is switched from the main fuse board as far as I know.

[Donutninja]

So what I understand is that I need to disconnect the red (acc) wire from pin 15 on the OEM harness?

I'll try that and see how it goes. Thanks for responding.

[Donutninja]

Alright so I figured out the solution to my problem. I needed to connect the red acc wire to an accessory wire but I actually thought pin 15 on the OEM harness was accessory, however there is no accessory on the OEM head unit harness. Instead I disconnected the red acc wire, purchased a fuse tap and connected it to the cigarette fuse (fuse 30). I also connected the yellow constant to fuse 23 (Digital tuner). The head unit now works when I turn on the car and actually turns off when I shut the car down.

[Donutninja]

Looks like the head unit drained my battery overnight after installation. I reinstalled the OEM head unit again.

Everything works, interior lights, headlights, brake lights, gear selector indicator, chimes, etc. However when trying to start the car, I put the key in the slot, foot on brake, press the Start/Stop button and nothing. I can hear the fuel pump priming but that's it.

I checked all the fuses and none are blown. I'm guessing it's a dead battery but I don't want to purchase another one unless I'm really sure it's the culprit.

I measured voltage on the battery yesterday and it was at 11.94V and then again today and it measured 11.68V. I'm almost convinced I just need a new battery.

Anyone else have any ideas about what the issue could be?

[ctuna]

you better charge that battery if you want save it with and external
charger.
How old is the battery ?
Normal battery life in benign conditions can be as much as 8 years if
the car does not sit around.
These cars are battery hogs even without adding aftermarket stuff .
You have to make sure the aftermarket stuff only has a tiny drain of shuts off
completely .

[Donutninja]

I forgot to mention. I tried jump starting with another car, jump starting with a standalone jump starter and also trickle charged the battery for hours. There is no change in the symptoms. All lights and electronics on except engine will not crank. No sound. Only fuel pump priming and that's it.

All fuses checked and are fine. I'm only assuming it's the battery and not the starter or relays as the car worked perfectly fine until the head unit was installed.

[Donutninja]

I don't know how old the battery is. I've only owned the car for less than a month and forgot to ask the seller.

[ctuna]

You might want to get the BMW diagnositc setup consisting
of BMW Stanadard Tools and Ista D . The people on the coding sub forum
may help you with that.

[Donutninja]

Quick update.

Turns out it was the starter that failed (coincidentally). Starter was replaced and has been working for a few weeks now. Only had the chance to reinstall the head unit last night. I used two fuse taps. The red accessory wire to the cigarette fuse (fuse 30) and the yellow constant to the trailer module (fuse 44).

Left it overnight and tested the battery this morning and it showed 12.23V so doesn't look like there was any parasitic draw.

I'm satisfied with it for now. Unfortunately the head unit does not turn on with accessory. It will only turn on with ignition. After reading a lot of BMW forums I've come to the conclusion that I'm not able to power the head unit via accessory on this car.