Contour Enthusiasts Group Archives Forums Modifications Audio Electrical Question - Pics

Ok, so there I was tonite, fiddling around with the sound system in my olds in a cold wet garage. You may have heard me talking about the horrible engine noise that is driving me to insanity. Well I was playing around with the RCA's and all of a sudden the noise totally flat out dissapeared! I nearly wet my pants I was so excited! It sounded sooooooo dead silent except for the beautiful music.

Now here's the kicker:
So after a few weeks of trial and error culminating tonite, I finally narrowed the noise down to this: The AIWA Mp3-CD player thats causing all these problems has a metal finned heat-sink looking plate on the rear of it. Well, if you unplug one of the four RCA's from the back of the CD player (any of the four will do) and touch the side of it to this heat-sink thing, the noise just dissapears totally.



When I discovered this I said, no problem, I just need to figure out a way to ground this heat sink thing. First I tried soldering a ground wire to the plate itself, but it wouldn't stick. Finally I unscrewed one of the screws that holds the heat sink to the cd player, wrapped the end of the ground wire around it, and screwed it back in. This did nothing..!!! Man i was pissed, I thought I was golden!!



And that's the picture of how I get the noise to totally dissapear. I have no idea what to try next. Theres got to be a way to fix this! Returning the cd player is not one of my top choices because I bought it in a different state (in order to be the first on the block to have this puppy, back in the summer)

Well, any help or suggestions you guys could offer I would GREATLY appreciate. Thanks,

Jake

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1994 Oldsmobile Cutlass Cierra 2.2
1995 Duratec MTX GL R.I.P.

[This message has been edited by JaketheSnake (edited March 16, 2001).]

You may have nicked that set of RCA's. Or does the noise go away if you do that to ANY of the RCA's?

Is this noise definatly in the head unit portion? I had a similar problem and couldnt figure it out. Either way this may involve your problem. What happened to me is one of the leads on the RCA on the inside broke from the circuit board. Whenever I ran that RCA it would make a very bad whining noise, just like engine whine but 4 times as loud, went up with the gas pedal and everything. I took it apart and re-soldered it and ever since then everything worked fine. Probably not the same but who knows it may help you.

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Madic
'00 Black SVT
1545 of 2150, Jan 13 00
madic99@hotmail.com

Hmm... you touch the RCA cable to the heat sink and voila, no noise. SO... Cut away a bit of insulation on one of the RCA cables, and try touching a wire from the stripped cable to the heatsink. IF you get all 4 channels, and no noise, make it permanent. if it doesn't work, use some electrical tape to fix up the RCA cable.

I don't know why this would work (electronically speaking), but if it does, you're golden.

Brian

Your engine noise problem is due to a ground loop. Its entirely possible that its a problem inside the head unit itself, or could be a bad ground at the amps, speakers, anywhere. Do you have power wires running alongside your RCA's? Because the RCA's are supposed to ground to the head unit chassis inside the head unit, and its possible they aren't. For a detailed explanation on grounding and engine noise, go here:
http://www.eatel.net/~amptech/elecdisc/caraudio.htm

Look up the heading "vehicule chassis ground". This website is, by far, the best and most informative web site I have ever encountered on car audio, and highly recommend it to all.
Let me know if it helps...

its gone, finally. after 3 weeks of checking and rechecking every component, wire, and connection in my whole phucking car i'm done. thanks, brian, i did exactly as you suggested and now i'm cruising with crystal clear sound.

man just in time too! i'm taking a five hour road trip tommorow to visit my old college. if i had to listen to the alternator go "WEEEEEEEEEEEEEEEEEEEE!!!" the whole time i think i would have lost it. thanks all you guys for all your help!

Peace, Jake

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1994 Oldsmobile Cutlass Cierra 2.2
1995 Duratec MTX GL R.I.P.

HOLY SHMOLEY!

I was right?! That's pretty cool! Glad I could be of help to you Jake. Hopefully someone on this forum will be able to tell us if this is a 'safe' fix, or if it's just a temporary solution. Either way, I'm glad that it worked properly. I repeat -- I don't know why it works (ground loops and alternators and yada yada yada aren't my forte) but I figured hooking a to b would help.

Woohoo... I feel like a million bucks.

Brian

Snake..

CDC-MP3 is what you have? Do you like it? Would you recmomend it..? I am in the market and was wondering what you thoughts are on that one.

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SVT 98.5
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Black 1998.5 Contour SVT
Build #6240
D.O.B 6/1/98
Still Stock -- (for now)

yes, i would recommend it, even though i seem to have gotten a slightly defective one. i love the looks, design, and the performance. people are always saying how sweet the thing looks, then i tell them the kicker (120-130 songs on one cd) and they're like damn, i gotta get me one.

one negative is the cd players inability to read over scratches on cds. if your uptight about it like me and keep your cds spotless and scratchless, than you have nothing to worry about. the few cds i have that are scratched up -- forget about it.

now that its working flawlessly again, i love it. heres a pic of when i was fiddling with it the other night. this thing really lights up your dash



peace

- Jake
[img]

grounding RCA's isn't uncommon...lots of people have to do it if they are running lots of channels...I have all 4 door speaker RCA's and my subs RCA's grounded...otherwise you can get that noise and sometimes grounding them will actually imporve signal quality whether you think yours is good or not....just do it somewhere unoticeable...i shaved part of my cable behinde my rear seat and grounded them to the trunk floor...made a big difference in the door speakers but no difference in the Subs...the Subs are less likely to need a ground because they are MONO and it's harder for the average Jack to tell if he is getting a bad sound out of his subs...but it's not uncommon at all....a lot of nicer stereo shops will do it on all amp installs just because it's one less problem they will have to deal with later....