Spark Plug wires.....noise issue

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What kind of noise do you get in your radio from spark plug wires? Is it a small popping noise or is it alternator whine?

I think I need some different plug wires...I am getting a little bit of noise when I turn my radio on.
 

slaughterj

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Well, I've only ******* about this noise for years! I'm guessing you had to go with some bling wires rather than standard Mopar black? Yes, it's a small popping and crackling noise.
 

joe117

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Alternator noise is a whine that changes with rpm.
Fuel pump noise is a whine or buzz that doesn't change pitch.

Spark plug noise is a popping of a static kind of noise that will change pitch with rpm.

With solid core wires, you would see by looking at the spark pulse shape, that you get a sharp leading edge and a sharp falling edge.

When a sharp edge pulse like this is sent down a wire, the sharp edge causes lots of radio signals at various frequencies to be generated.

Why?
Don't fight this. Take my word for it.
They are called "harmonics".

These signals that are generated are received by your radio. They can also get into your CD player.
A car parked next to yours might also pick up the noise.

Resistor wires round off these pulses and cut way back on the generation of harmonics.

I see that you have a supercharger. You may need solid core wires in order to get the spark you need.
Stock or near stock engines don't need these wires.

Why did you change to solid wires? Did it do anything to improve your performance?

If you didn't see any increase in performance with the solid wires, go back to the stock wires.

If you find that you need the solid wires, the only way I know to limit the radio noise is to shield the wires with grounded braid.

The popping noise is getting into your radio through the antenna. Filters on the DC power line of the radio will not help.
 

Gerald

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yup.. ab if the whine goes up and down with RPM, that is Alternator noise. The fix could be as simple as sheilding your wires from your head unit to your amps, etc. Have you tried to change out your RCA cables? Upgrade your cables?


Gerald
 

joe117

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If you had alternator noise, it would be getting into your system through the power input. A capacitor to ground at the alternator output is a typical filter that may help with alternator noise.

Shielding the wires from your head unit to your amps is probably not going to help with alternator noise because the noise is not being transmitted through the air.

High priced RCA cables are really no better than good Radio Shack cables selling for typical prices.

There is a big audio/video industry out there trying to sell wonder cables at gigantic prices to people who don't know how cables actually work.

Lots of pseudo science in the audio/video cable business.
 

VPRTKMIKE

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Also try connecting the ground strap that is located on l/s of cowl panel near foot box , remove rear most stud sticking out of valve cover for wire looms and connect it there. I found it cure the noise with the mopar perf. wires.
 

KenH

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Also try connecting the ground strap that is located on l/s of cowl panel near foot box , remove rear most stud sticking out of valve cover for wire looms and connect it there. I found it cure the noise with the mopar perf. wires.

I noticed this ground flapping in the breeze on mine, and was sure it was suppose to be attached to something, but I could not find a reference to it in the manual. Is this ground braid normally left unconnected from the factory?
 
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