Revisiting Pioneer Head unit Installation on a Logic7 car... Parasitic draw??

[D.I.P.]

So a few months ago i went ahead and installed a Pioneer AVH-5600BHS Head Unit into my 09' 135i with L7 or "Premium Audio" as it was know back then... I successfully (sort of) installe dthe head unit and got it working fine after realizing i also needed to replace the factory L7 amp. So, i went ahead and installed a JL Audio 600/6 amp and everything was working great.... for a short while.

Original Install thread:

http://www.1addicts.com/forums/showthread.php?t=1024223

Everything was fine for a month or so until i let the car sit for a couple of weeks. When i went to start the car one morning, it was dead... OK, no big deal i charged up the battery overnight all was well again the next day. Maybe i left my interior lights on or something? i thought to myself... Long story short this kept happening when i didn't drive the car for a few days to the point that i got this:

http://www.1addicts.com/forums/showthread.php?t=1077491

I replaced the battery but that didn't help as you can see from the thread i linked above. I eventually removed the entire audio install and reverted everything back to Stock and re charged my old OEM battery and the car has been fine ever since, even when i let it sit for a week or two...

So clearly the Head unit/amp install was creating some kind of Parasitic drain on the battery. The question is how? or why? I used this exact wiring diagram when i installed the radio/amp... (see attached) What do i need to do differently to avoid the same problem? I would really like to use the aftermarket radio and all of its convenient features that my NON-NAVI stock radio does not offer...


Any thoughts?

[reisf]

Hmm is your mulf/tcu/combox still in the car? I'm thinking If you removed the factory amp this may cause these to not function correctly (i.e. not power off) as they are all connected in series via a fibre optic connection.

The only real way to find a parasitic drain is to pull your fuses but because you have an aftermarket sound system, it should be a lot easier to find by pulling the fuses that correspond to the cars multi media devices

[tracer bullet]

The simple idea would be to see if the amp is always on, whatever you used for a switched lead may in the end not have been switched like you thought?

I have been fooled before, working on a stereo on a different car and having the car doors open for so long the ECU turned the interior lights off so as not to drain the battery. That made my multimeter checking job around the fuse box for a switched 12V lead not give me "real" results! I had the amp turned on 24 hours a day and after the car sat for a week or so the battery died. Easy fix but definitely got fooled even after being pretty sure I was good to go.

The recommendation above from reisf is interesting, not something I'd have thought of.

[D.I.P.]

The remote amp Turn-on on lead was wired to the amp turn-on wire on the Headunit Harness it self. I did confirm that the amp turned off when i shut the car down.

[reisf]

Since i'm guessing you don't have idrive in your car, you would have had the BMW professional/Business head unit + some sort of bluetooth capability?

If you had bluetooth capability before you installed the pioneer head unit, you need to know that the bluetooth is not controlled from the BMW factory head unit. There is another module in the car that controls the bluetooth/multi media and it is stored in your boot under the trunk liner. These are the MULF and Combox (you probably had an MULF). If you have BMW Assist, you may also have a TCU in your trunk in addition to the MULF.

This would connected via fibre optic connection directly to your factory head unit. Think of this as the BMWs remote amp turn-on. Now if you did not remove this after you installed your Pioneer head unit, my thoughts are that this module is always staying on, because if the fibre optic connection is broken, all multi media functionality will cease to operate correctly, if not, at all.

Now because you have tested your aftermarket amp and checked that is turning off, and the fact that when you revert your entire setup back to stock, that you dont have this problem - i think this may be the cause of your drain. I say this because the MULF has the "brains" to stay on after the car is turned off. For example, if your making a call through the car's bluetooth and the call is still active when you turn the car off, the call will not disconnect and the head unit and MULF module will remain on until your call is disconnected

So if you had bluetooth from factory, all im saying is - pull the thing out, you don't need it anyway with your new setup. Plus weight reduction bro

[D.I.P.]

my car does not have Factory Bluetooth or BMW assist.

[JimD]

Did you know you can measure what current is flowing with everything "off"? I use an inexpensive multi-meter I got at Walmart for maybe $30 that has an amp setting. It will only measure low current levels but that should be where you are. You disconnect the battery and then put the multimeter in between a battery lead (they suggest negative) and the battery. You read the current. Then you can pull one fuse at a time until you find the one with the draw. In your case, you should know which circuits have the radio load so you could just pull those.

This won't fix the problem but will help you determine where the problem is.