wierd noise through speakers when breaking please help me

[csumner2020]

I have a system consisting of a pioneer head unit, 2 12" woofers, 1200 watt mono amp, kicker mids, and kicker tweets along with a kicker amp. I got in the car this morning and noticed this high pitch sqeeling sound coming from mids and highs. Upon closer examination I noticed it only came through when I hit my brakes, it almost sounds like somekind of fm interference; very high pitch and stops and soon as I come to complete stop, also only does it when I'm braking from high speed.
I thought about it being some brake light short bleeding onto signal wires but if that was the case it would sound whenever I brake, thought about it being somekind of antilock brake problem, pulled the fuse and still the sound comes through when braking. I am having this noice from all sources: am/fm, cd, aux input. Anythoughts would be greatly appreciated.

 

[Mjaga251]

Only thing I can think of is to check all wiring and make sure none of the coating was rubbed through and now has metal rubbing on the wires.. This happened in my old explorer. The coating rubbed away by my brake pedal, where it went through the firewall and sometimes there'd be a loud screech from the sound system when braking.
Hope that helps.

-Mike

 

[csumner2020]

thanks mike to give a better description of the noise imagine someone scratching records my friend said its sounds like a little dj in there or something. when i turn my cd player to vol. 0 it wont happen but on 1 here it comes and its intemident.

 

[Mjaga251]

Any luck on figuring it out?
Still the only thing that comes to mind would be the wiring.
I'll keep my eyes and ears out for any other info from my buddies.

 

[csumner2020]

NOOOOOOO,
i went into a local shop today and they were dumpfounded. They think its the HU but doest make sense adding in the fact that it only does it when I hit the brakes. I've connected like an mp3 behind the cd player to the rcas that run to the back of the xp to the amps and I dont have the problem so I know its coming from the cdplayer but its got to be coming through a power wire ground something. i'll be taking it to another place in a day or two I'll post afterwards. thanks for checking up let me know if you hear something.

 

[Turdle]

Did you check your brake light bulb sockets? They could be corroded.

 

[csumner2020]

True but if that was the case i would do it sitting still it only happens when i'm slowing from bout 20mph or more, and it stops as soon as the car stops even though the brake lights are still engaged, good thought though

 

[budwich]

It doesn't have to be an external ground / power lead problem. It truly can be an "fm" problem.... maybe a problem in the demod section in your HU not having proper shielding or having some form "cold solder joint diode" that is "rectifying" a "free to air" signal coming from somewhere.... its probably always there but the demoded frequency is only audible during the observed times.