haven2893

Hi everyone need help here. My accesory shop guys just fixed a subwoofer for me.
The speaker wire was tapped off my right B Pillar and the power cable was taken from the power input to the auxilary battery. Right after it was dine and tested working, the car showed the following fault codes
1. runflat indicator inoperative
2. Adaotive headlamp inoperative

Also noticed my 360 camera, seat belt pretensioners and auto hold stopped working.
Anyone knows what may the cause be pls?
Thank you

S-Prihadi

Remove power +12V and the negative too, of the new subwoofer, this subwoofer has a built in amplifier right ?
Scan for codes using decent scanner, take photo of codes show us, ERASE CODE. Test the car : If all back to normal, you are lucky because probably nothing is fried yet.
If above solve your problem, there is a possibility that the : "the power cable was taken from the power input to the auxilary battery" is actually being connected to the OUTPUT of the AUX baby battery.
This is the start stop version ? 12Ah baby battery at the trunk and main battery 80ish amps at the engine bay...?

If what I wrote in orange and underlined is correct, that AUX battery during disconnect to main battery ( this AUX battery is not always connected to MAIN Bat ), become an unwanted +12V injection to your car electrical system ,
like a parallel 2nd battery connection but thru small audio wires.

Good luck........

CaliBenzDriver

This is your car telling you it does not care for your new subwoofer accessory:

1. Runflat indicator inoperative
2. Adaptive headlamp inoperative
3. 360 cameras
4. seat belt pretensioners and
5. auto hold stopped working

Check available voltage is near 13V?
Don't rely on the engine alternator to perform battery miracles for you.
Charge your main battery full with a battery charger. That way battery provides a low-internal resistance that can smooth out troublesome riples.


> Engine ON:
Don't even think about blasting your boombox without running the engine to supply power.
Low-voltage is disrupting unstable modules and bring the Xmas-Trees conditions around the corner for you. The large voltage riples are also prematurely aging every module undersized capacitors. These poor capacitors make the whole car less tolerant to its own glitches.


Connecting a large "FARAD CAPACITOR" may help smooth woofer riples in an otherwise good circuit.


> POWER = GND :
Speaking of power, a good return back to GND is as important as the +14V path because it sees identical high current.

Your woofer return line goes to un-shared separate chassis GND screw but that's still only half way to the alternator!

You need a good Chassis-Tranny GND strap. Is yours still workable?
Either spend time testing the riple drop-voltage under load with a scope or simply go ahead to add a secondary GND strap now.


> ALT HOME RUN : <<<< --- SHORTCUT !
Forget about using any of the existing car harness.
The car power distribution involves fuses and solid state relays that occur drop-voltage that you don't want.

Go ahead and wire up your power feed directly to the alternator.


+++++++ QUALITY IMPROVEMENTS

> DUAL-PATH HOMERUN ?
These issues are caused by high amp current spikes that causes high voltage-drop riples on the existing harness.


To fix this problem:
you need low-impedance power supply with few connections that need to be excellent to prevent drop under high load.
With that said, it becomes obvious a DIRECT HOME-RUN is your silver bullet.


Faster is cheaper, right?
No need to mess around splitting-hair on this or that buggy Benz module... simply focuss on creating your own power feed -/+ loop going outside of all the undersized MB circuitry.

Don't ignore the GND return that has exactly identical current - Homerun GND to block for woofer system maybe a good idea while wiring the positive side.... HOMERUN BOTH -/+ TO ALT
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