running lights/head lights on and radio speakers hum?

[sacky07]

So my dimmer switch is acting up and i was in there swaping it out. when i had the new one in and turned on the lights i noticed the radio speakers were humming, put the old dimmer back in same result. Guess i never noticed it before with the old switch. The car has the factory stereo but someone had a cd changer hooked up, could this be the changers dimmer wire causing this humm? When i brighten/dim the lights the speaker crakles and hisses. I believe its only the passenger rear spaeker thats making all the humming n hissing. I dont understand why the dimmer switch would cause spaeker noise??

 

[sacky07]

nobodies had this issue wtih the dimmer and speaker??

 

[mob]

Are the speaker wires factory and in the factory locations? I am pretty sure any speaker wires routed near power wires can cause engine noise to travel through the wires. Not sure as to why it just started happening though. You may want to try and install one of those inline noise filters, that's the best advice I got.

 

[jrichker]

Autozone: Electronics/In-line noise filter Part Number: AW-NSFL Price:$9.99

 

[sacky07]

well i got the dash apart and didnt see anything suspcious, and its time to reassenble. Guess i will try one of those noise filters. Where do those things get wired in at?

 

[jrichker]

In series with the power feed to the radio. Ground the black wire to a good clean bare metal part of the car body.

 

[HISSIN50]

Were the grounds up to par? IMHO it's better to fix the issue than try to mask it.

 

[sacky07]

I didn't check any grounds, just looked for spliced wires. I thought I was goin to find something with the orange iluminarion wire but I didn't

 

[sacky07]

The radio works fine when the running/head lights are not on and when you dont mess with the dimmer switch. Where would i start to check grounds?

 

[HISSIN50]

I'm not clear about when you actually hear noise exactly, but check the ground for the deck. I'd also look for bad speaker wiring connections (you noted an aftermarket deck). Ensure the antenna connections are tight and the ground on the hood (if applicable) is intact. Ensure the body and engine grounds are clean and sufficient.

You don't have an amp, mp3 player or other aftermarket equipment, no?

 

[sacky07]

OK, got the car put back together. The radio is factory, although someone cut out and put back in the stock wiring harness. It all seems to be hooked back up correctly. Now to the hissing noise. While taking the car for a spin with the lights on, i noticed the hissing or whine is associated with the engine rpm's. Rpm goes up, the whine gets higher pitched. Rpm goes down, the whine gets lower? Is this common with bad grounds, to pick up engine "harmonics"?

 

[jrichker]

The alternator may also cause noise in the radio due to problems with the voltage output. Sometimes instead of being a steady voltage, it has spikes and dips. These may not show up when the alternator is bench tested.

 

[sacky07]

I did install a powermaster 140A alternator(before i learned of the 3G upgrade ). Its a one wire set up, but had to splice a wire into the existing harness on the car according to the directions. I wonder if that has anything to do with it and how.