I have tried everything except changing the plug wires and I still have static and poping
coming from the stereo. This only happens
when the car is running. I hooked a seperate
12 volt supply started the engine and I still have the noise. Bench tested the stereo and no noise just music. I am running a MSD 6AL and dist.
The noise you are hearing is coming through the 12 volt power line. Maybe sounds like a whine that changes frequency has the engine speeds up? You need a filter choke coil on the 12 volt line behind the radio. Should be able to get one from Radio Shack or any place that does car radio instalations. Somewhere around $5.00. It's easier to filter it than try and figure out what's causing it.
Possibility that it's coming through the antenna but try that first.
[This message has been edited by John_Muha (edited 02-04-2002).]
<BLOCKQUOTE>quote:</font><HR>Originally posted by John_Muha: The noise you are hearing is coming through the 12 volt power line. Maybe sounds like a whine that changes frequency has the engine speeds up? You need a filter choke coil on the 12 volt line behind the radio. Should be able to get one from Radio Shack or any place that does car radio instalations. Somewhere around $5.00. It's easier to filter it than try and figure out what's causing it.
Possibility that it's coming through the antenna but try that first.
[This message has been edited by John_Muha (edited 02-04-2002).]<HR></BLOCKQUOTE>
I have a filter that I installed that installs before the Alt. that took care of the whine. I also ran a # 8 to the battery for my ground and I still have the popping and static. I also tried installing a filter in line with the power that feeds the stereo still popping and static. Any other ideas?
how close is the ignition box mounted to the stereo? where are you getting power for both of them? does it do it only when the radio is on, or also when a tape or cd is in?
ideally, they should be mounted as far apart as possible, and try to get the power for them from different sources.
keep the antenna wire away from the ignition box.
make sure all the grounds in the car are good and solid- battery to engine, battery to body, engine to body. you can really never have to many- or too big- grounds. make sure both the ignition and stereo have individual grounds to clean metal.
------------------
1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels
see pics here http://community.webshots.com/user/novaderrik
Great ideas about grounding, but it sounds like you have looked into it. Novaderrick has a good point. Is it popping only when the radio is on? Is it an occasional pop or is it consistent? May narrow the problem down to a transmitted problem versus a power supply noise problem. This used to be fairly common when spark plug wires were solid wire. Cars would go down the street messing up all the TV sets.
Great ideas about grounding, but it sounds like you have looked into it. Novaderrick has a good point. Is it popping only when the radio is on? Is it an occasional pop or is it consistent? May narrow the problem down to a transmitted problem versus a power supply noise problem. This used to be fairly common when spark plug wires were solid wire. Cars would go down the street messing up all the TV sets.
I bet if you take your #8 ground wire that goes directly to the battery off and ground to the frame close to your radio, some if not the majority of your whining noise will go away.
I had the ignition noise comming through my am/fm radio in my truck, turned out to be a poor antenna wire connection. I cleaned it up and it's fine now. try that, or rig up an other antenna.good luck.
<BLOCKQUOTE>quote:</font><HR>Originally posted by John_Muha: Great ideas about grounding, but it sounds like you have looked into it. Novaderrick has a good point. Is it popping only when the radio is on? Is it an occasional pop or is it consistent? May narrow the problem down to a transmitted problem versus a power supply noise problem. This used to be fairly common when spark plug wires were solid wire. Cars would go down the street messing up all the TV sets. <HR></BLOCKQUOTE>
The 6AL is mounted to the fire wall on the passenger side. They are both fed from the fuse panel under the hood. The 6AL is fed from the ignition switch, and the radio is fed from the panel, but both feed from the panel. I tried moving the ground closer to the amp that did not work either. I'll try running a feed from the junction spot behind the battery with a fuse in line and see if that does anything. The car makes the nosie with a CD a tape or radio. The noise is constant and only when the engine is running.
I am using Talyor Spiro Pro wires which are supposed to help with the noise.
Still scratching my head. Someone suggested the antenna. Have you tried running the CD with the antenna disconnected from the radio? Another thing is I assume this is a one piece stereo, not a two piece with a separate amplifier.
When I had a similar problem, it turned out to be the ground strap to the back of the radio. Vibration caused movement and, in turn, popping noises. If the external ground is O.K., then I would look internally to the radio. The ground generally is continued via a wire to the circuit board. Those connections have also been known to have problems. I would also, of course, look at the 12V connections. The key is the description of "static and popping" which indicates power/ground or signal interruptions. Unfortunately, you did not indicate (that I noticed) whether the audio was interrupted or not. If a simultaneous interruption of audio occurred with the static/popping, then I would look in the signal loop. There is/are filter capacitors across the 12V to ground path which would allow continuation of the audio during the problem for a short period, and then taper down in volume. A signal loop interruption will cause an immediate non-audio signal condition while "noise" will continue on.
<BLOCKQUOTE>quote:</font><HR>Originally posted by BobMcC: When I had a similar problem, it turned out to be the ground strap to the back of the radio. Vibration caused movement and, in turn, popping noises. If the external ground is O.K., then I would look internally to the radio. The ground generally is continued via a wire to the circuit board. Those connections have also been known to have problems. I would also, of course, look at the 12V connections. The key is the description of "static and popping" which indicates power/ground or signal interruptions. Unfortunately, you did not indicate (that I noticed) whether the audio was interrupted or not. If a simultaneous interruption of audio occurred with the static/popping, then I would look in the signal loop. There is/are filter capacitors across the 12V to ground path which would allow continuation of the audio during the problem for a short period, and then taper down in volume. A signal loop interruption will cause an immediate non-audio signal condition while "noise" will continue on.
<BLOCKQUOTE>quote:</font><HR>Originally posted by Dave Brinson:
<HR></BLOCKQUOTE>
Bob,
The noise is continuos and is louder as you turn up the volume. When you say Audio loop from the stereo to the Amp? The stereo is grounded via a hanging bracket on the back of the unit. The Amp is grounded to the battery. I’m a wit end here. The bazaar thing about this is I have two 69 Camaros the one that is having the problems is my sons driver. Same stereo from Custom Auto sound. different amps. Yesterday I bought a Rockford Fosgate to try but I really don’t think that it will help. I’m really grasping for air now, about to give up.
Dave -
At this stage, I would consider re-checking all your connections. If your radio receives it's power and RF through a captive connector on the back, then use a magnifying glass to inspect the pins - do any look broken/pushed in? If it receives power and RF via seperate plug-ins, then you can check those by pulling/pushing/twisting them while the radio is on and the car running, by listening for any changes. Also while the radio is on, and car running, thump on the radio and it's connections to see if any sound changes happen. Is it possible to swap radios in the two cars to see where the problem reappears - that could narrow it down.
Bob
Wouldn't the separate amplifier feed line (12v) also need to be filtered? If I understand everything they are 2 separate units. Filtering the alternator only cut out the frequencies from that source. Filtering the deck helps. If the amplifier is another unit, perhaps that's the way it's getting in. Still scratching.
I'd recommend backing up and ensuring that it is power line interference and not broadcast noise. Typically noise with the CD means power line, but a quick check with a handheld radio on AM is easy to do. Google Curing Radio Noise Popular Mechanics; they wrote a pretty good article about it. Just fixed a radio in a '69 with the same ignition where the distributor cap's center pickup had broken loose and was connected enough to still run but enough of a gap to cause noise at the same frequency as the rpm.
Might as well keep the thread going! I'm basically in the same situation. High pitch whine that increases in pitch with increasing rpm. Still working through checking everything and revising the wiring where ever there is the possibility that it will lead to a cure. One thing I will not do is add a noise filter. Pretty much every place I spoke with that does quality car audio has advised against installing them as in addition to it filtering out the "bad" audio, there is a high likelihood that it will eliminate high frequencies that are close enough to the bad audio but are actually part of the music being played. This is a great thread as its a common problem with lots of factors and root causes. Also lots of misinformation.
If you can access all your audio grounds,tie them to a temporary jumper of appropriate gauge,and ground it to different points on the chassis,even try a neg battery ground and see if it stops the whine.
Hey Mark, just saw this 5 weeks latter. Last winter, I did a motor swap along with some other major mods. I am using a different coil than I was before the noise surfaced. When I swapped motors, I went from a MSD Blaster 2 to a MSD Blaster SS part # 8207 an added an MSD Digital CDI box. While I used all the same stereo components, I also did a lot of rewiring to the stereo system. I'm 99.9% positive that I did not have a noise capacitor before the swap. Was I just lucky before? Are these really a must part of the electrical system? Thanks!
Still confused as whether all cars should have a noise capacitor and have it installed on the (+) side of the coil and how much a CDI box contributes (if at all) to the whine. Both the alternator and battery are new. I believe I've done an adequate job making sure grounds are clean and secure; and that all wires for the stereo and amp including low voltage/preamp cables are routed away from other wires. Thanks!
Sometimes when you have alternator "whine", it might be an alternator failing to where it's allowing more AC signal to be on the DC output and have also seen batteries that are getting weak as the battery also acts as a stabilizer and acts in a sense, as a filter smoothing out any AC ripple.
Also keep in mind, a lot of capacitors internally dry out over time reducing their filtering.
Thanks Jim for the advice. I've gone through all those recommendations. Wish I could report an improvement but still the same. Still haven't heard from anyone regarding the necessity of the noise capacitor that is shown on that diagram earlier in the thread.
In the same way that capacitors can act as high-pass filters, to pass high frequencies and block DC, they can act as low-pass filters, to pass DC signals and block AC.
Instead of placing the capacitor in series with the component, the capacitor will be placed in parallel.
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