From digest.v7.n21 Wed Jul 30 07:04:31 1997
From: Kim Watters Halapin <zgbjtjh_at_snt.bellsouth.com>
Date: Tue, 29 Jul 97 15:51:31 EDT
Subject: Re: <E36><M3> Stereo upgrade self-install, ignition noise

Kirk,

I seem to remember a similar problem with with a '95 M3 a while back. I shared my experiences with my E34 stereo upgrade with him, specifically the problem getting rid of the alternator whine. While you are experiencing ignition noise, both can feed back through a noisy ground. To the point, the solution was to cut the ground wire at the head unit and splice in a wire grounded to the bracket. Again this was to eliminate whine, not ignition noise but you might want to give it a try.

Standard disclaimers apply.. not a stereo installer, not a mechanic, etc.

Regards,

Kim Watters
E34/530i/5-speed
MBQuartz QM215.03CX's front, MBQuartz QM130.03CX's rear JL Audio 8W6 subs, SoundStream Reference 705S amp AudioControl EQQ, Kenwood PS905

> From: "Kirk Shafer" <kirk_shafer_at_smtpgate.tais.com>
> Date: Fri, 25 Jul 97 11:22:11 PST
> Subject: <E36><M3> Stereo upgrade self-install, ignition noise
>

>      Has anyone performed their own stereo system upgrades on a late model 

>      E36 and battled ignition noise?
>      
>      If yes, what solved noise problem?  Wire routing alone, amp mounting 
>      isolation, shielded cabling, were 12VDC in-line filters?
>      
>      I removed stock amp.  Replaced with a line-level converter (to get low 
>      level signals to work with), one 3-way electronic crossover unit, 3 
>      amps (parallel-connected some speaker pairs).  Having much trouble 
>      eliminating a constant-volume ignition-correlated whine.  Assuming 
>      ignition noise on 12VDC lines coupling into low-level preamp signal 
>      conductors somewhere.  Driving me nuts, especially since I'm an EE and 
>      have done numerous stereo and feel like I should be able to fix this!!
>      
>      Thanks for any advice, professional or otherwise.
>      
>      Kirk S
>      97 M3