2G Airbag ECU interference

[Pablobtown]

So after trying to chase down a high pitch whine for over a year I finally found my culprit. After multiple amps, patch cables, headunits, and even a 200amp saturn alternator upgrade. I'm still left with an awful whine through my speakers. I was rerouting my patch cables (for the millionth time) and noticed the closer the patch cables and/or the headunit are to my air bag ecu (under center console) or the wire lume coming from the AB ecu (that runs right next the headunit) the louder the whine gets but I can't get it silent or any bit quiet no matter where the cables go. And nobody seems to have any issues I have. All the factory wiring is untouched other than my audio install. I have no srs light or anything. Any ideas?

 

[luv2rallye]

I've never heard of that. A whine is usually the alt or a bad noise filter capacitor can on the intake manifold. 1) As a test try disconnecting the alt and see if the whine is still there. 2) Replace the 0.20uF capacitor. 3) If everything else fails try shielded cables (with shield to ground on both ends). 4) Do you get the whine when engine is off or when key is on but engine not running? 5) Do you have some grounds missing or poor connections?

 

[Pablobtown]

I get the sound when the key is to acc or on (car running or not). I thought about the capacitor. It's a bipolar .2uF cap right? Sound is there with the alt unplugged also. Thanks... also I have shielded rca cables, and am going to grab a pair of xlr (balanced) and see what I can do with those...

 

[Pablobtown]

I grabbed a .20uF bipolar capacitor and swapped it. No difference.

 

[luv2rallye]

Many air bag ECU's have a dc to dc converter in them which usually involves an oscillator - thus a possible noise source. Perhaps yours is defective or no longer properly grounded. You could try replugging it or checking it's grounds or unplug it just to prove if that's the whine source (but first disconnect the battery and wait 60 seconds for any internal charged capacitors to dissipate and I'd still keep away from being in front of the air bags just in case).

 

[Pablobtown]

If I unplug the air ECU the sound goes away... Ok so I either have a sound system I can stand or... I can live in an accident... Tough choice

 

[luv2rallye]

Can you reroute the wires somewhere away from the ECU?
Are you sure your radio/amp is grounded ok?
Or get a different ECU.

 

[Pablobtown]

I've rerouted the patch cables every way possible... Doesn't matter how far away it is. Because that lume runs less than an inch away from the head unit and where the RCA's plug into the head unit is right at the same side as the lume.

 

[Archer Fabrications]

Ive got a 2g srs ecu I'm not using (drag car) if all else fails

 

[stars]

Aluminum foil over the wires, it can reduce the amount of EMF that gets inducted into nearby wiring. It also acts as a shielding plus it costs nothing to buy on a budget that has none =). Hope it works

 

[luv2rallye]

Probably will have to connect the foil to ground for it to work.