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Engine through the radio.

P

Pen_Two

Is not easliy amused.
Joined
Mar 10, 2006
Messages
9,874
Location
Union Dale, Pa
Well, it abruptly started happening yesterday. I can hear a whine through my radio that increases with the engine speed. If I turn on my headlights, it gets worse. I tried a 20 amp in-line noise filter on the radio and it did absolutely nothing.

Is it safe to assume I should try spark plug wires next?
 
Whine is most likely a diode pack in the alternator. May not show up in a voltage test but will be low on amperage. Wires don't really sound like a whine.
 
So if it turns out to be a diode pack, replacing the alternator is the only thing to fix that? :blackeye:
 
Unless you replace it yourself (rarely done). I'd check your amp and radio grounds first, and battery connections.
 
It's an intense whine with the lights on. With the lights off it's a quieter whine, but there's a pulse on top of it. If the ignition is in the ACC position, no noise in the speakers. If I turn the lights on, it still has the high pitched whine. I can also hear the windows going up/down through the speakers as well.

I unplugged the power antenna just to see if it was causing any interference with the batter which is mounted right next to it. It didn't make a difference.

I checked the grounds I could find, but I'm not sure just how many there actually are.

Here's a quick question. Will the battery being mounted in the trunk make the alternator test at Advanced auto any less accurate considering the distance the current is traveling is increased (I'm not big on electrical work).
 
Alright, today I tried new spark plug wires and it didn't do anything. I got the alternator test and they said it also checks the diodes, they came up fine.

Tomorrow when it gets light out, I'm going to bypass the amps and see if it still does it.
 
A little late on the update since I was working, but I re-grounded both amps AND the battery (it's in the trunk). No luck with that. I disconnected the amp and hardwired the speakers to the CD deck...and they played fine. The RCA's are ran directly down the middle of the car, and the main power cable for the relocated battery is on the passenger side.

I feel like I'm missing something easy. It was suggested to just pull the 4-channel amp, but I think the bridged amp powering the sub also would have to be pulled since I get a loud bass-filled pop when I shut the car off. :blackeye:
 
I also took a spare speaker wire and connected it to one of the RCA jacks on the 4-channel and ran it to the ground on the radio. It improved the noise, but it was still there.
 
dude i have the same problem the more high end things i add to my system the worse it gets. now i need to replace my mega fuse. after i replaced my altenator it still did it but it was less. then i put a rca ground loop in and im pretty sure its due to my crappy mtx amp in the back that has been fixed 2 times i think. just turn it up so u cant hear it anymore
 
There are many things that may cause this problem. And without know what your setup is (every amp, wire, speaker, etc.) It sounds like more than just a bad ground. It sounds like a current is being induced (bleeding) onto your wiring. Cheeper and non shielded wiring can cause this. Basically all electronic equipment puts out a small electric field. This field is picked up by other wires. The more you have the worse it gets. It gets pretty complicated. This is one of the times that money does buy quality. Never buy cheep wires. With that said. Check the wires from the battery. If either one is wrapped around another wire, this will cause bleeding. Once this happens, every amp in the line will do exactly what they do, amplify the noise. Also, all your amps should be in the same place so you can make sure they are all grounded to a common grounding block. You can also try grounging the amps to each other. You could also have a bad amp. Now, when I say this, I don't mean the entire unit. I don't want to get to technical, but each amp has many smaller amps inside it. If even one of these is bad, it will only get worse the farther down the chain you go. I hope some of this helps.
 
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Well, to put a close to this...it seems that the Pre-Outs on my deck went bad :)shrug:). I wasn't aware that could happen. Tried another deck courtesy of LUCA and the problem pretty much stopped.
 
Sounds like your amp is bad, did you try running new RCA's from the HU to the amp to see if the RCA's are still working good.... Alternator wine is usually a cause of bad grounds, Some rca's come with a reference ground to better "level" the ground between the front and rear grounds (radio and amps). Most people think the wire in between the rca's is for a remote turn on, but in actuality it's for ground. I'd try new RCA's, and if that doesn't do anything, as big of a pain in the ass as it seems, I'd try a new 4 channel..... Odd that your getting more feedback though when the headlights are on, do you have any pictures of your wiring behind your HU and at your amp? They would help if you could....
 
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