Orznick14

Just installed an Audison AP F8.9bit (1200W) and head unit on my 04 E55 AMG. Drive around with it hooked up for a couple days now and finally got everything buttoned up last night. Never listened to the music loud, just 7 or 8 since my center speaker rattles and left side is out.

Sorry for the long block, it’s story time hopefully it helps troubleshoot.

So I get in my car after work today and get the battery protection message. Don’t think too much of it, maybe I switch the head unit to only run on the cigarette lighter and not tapping into the old radio power. 3 mins in I get a red battery warning. Stopped and checked connection, everything is good. 5 mins later I get the red battery/alternator message and air turns off. A minute later I get the SBC stop immediately reduced braking power etc messages. Stopped at a gas station on the way home and took the fuse out of the amp power wire (no tools in the car). She JUST barely turned over, so I started driving again with the brake message since the brakes felt perfectly fine (safety). Found that if I held it at 2500-3000 all of the battery messages go away. 5 mins later huge puffs of white smoke behind me. Stop and see it’s coming from the engine bay. Eventually got it jumped and started, ESP SRS and ABS lights all blinking, car didn’t want to upshift at all. Home now and an alternator on order. Auxiliary battery voltage is perfect 12.3. Main is 10.8 after driving and stopping. With the car running battery was 11.5ish.

Do you guys have any reason to believe it would be anything other than the alternator as well? Main battery is 3 weeks old. Really good quality AGM.

Plutoe

things use energy and things generate energy-----now restate your problem or what is your real problem

Orznick14

wanted some general opinions on if a stock alternator and group 49 battery would be able to handle the normal electronics in the car plus a 1200W amp.
But since I wasn’t listening to anything loud, I don’t think I overloaded the alternator. Didn’t know if there was something that could fail and cause all of that to happen outside of the alternator or voltage regulator

Sandygear

I use a 900 watt sub amp and 200 watt 4 channel and I play that loud as often as I can. It's a good idea to have a new battery and alternator as part of the package so as to not upset the other computers.

CaliBenzDriver

You know the ALT on these cars does not put out a simple 14.4V... it output what the ECU request. Unfortunately the ECU has no idea you need 1500Watts to play loud music so battery is forced to supply the power your ALT does not.


You need to study what ppl before you have done to extract power for their amplifier.... I am thinking about duplicate GND cables, Farad capacitor and direct home runs.

Creating high energy ripples currents help age undersized capacitors in all 12V modules... rendering them more and more unstable. Not what you want.

Orznick14

Fair enough, thank you for your input. No issues since replacing the alternator and voltages are rock solid so I think I am okay. running stock speakers and I don't need to upgrade the sub anytime soon. Don't listen to my music loud anyways.

Orznick14

I will look into those options. I rarely have the music loud, max 10 out of 50 on my head unit (not that means anything), so I think I'll be safe for now. Defnitely not pulling close to the power the amp can supply.
Thanks!