2007 Grand Marquis: Hum in R/N/D/3/2/1 but not in Park. Help!

[1991Brougham 10+ year member]

Not an alternator hum. It's steady and low but noticeable. No noise in Park as the subject title says. The HU is an Alpine and the amp is Kenwood. What's wrong?

Rick

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[jrdnhsnbrg 10+ year member]

That car fwd, rwd, or awd? Where are your power and RCA wires ran? Anything close to moving parts?

 

[CrossoverOre 10+ year member]

Whats up oregon. so im assuming we are talking about a 4ch amp with noise coming out the midrange speakers. with the current settings at what volume on the alpine do you hit max volume level? Did the speakers get rewired or using the factory wires from behind the head? Did the problem ever not happen or has it been an issue from the time of the install? What type of rca's are you using? are they ran on the opposite side of the power wire? Double check grounds. try connect mp3 device directly into the inputs of the amp and see if it still happens. was the factory setup a "premium" system with a factory amp? a little more detail on the system and what you are running will help.

 

[1991Brougham 10+ year member]

You assume correctly about it being a 4 channel amp COO. Max volume is irrelevant other than if you turn the amp enough, it drowns out the hum. Don't know about the wires used for the speakers as it was done at a local shop, who has never seen this problem before BTW and these guys have been doing installs for close to 30 years. It was a problem right off the get-go but my friend didn't know enough to say something. He's new to car audio. No idea about the RCA's as I didn't do the install nor do I know how the wires were run. The hum occurs on all modes of operation. The factory radio was the standard AM/FM/CD unit, not the premium 6 CD one with subwoofer.

Jordan (?), the Grand Marquis along with the Crown Vic and Town Car are RWD's. Everything is close to moving parts. It's a vehicle after all..LOL!

My guess: Going out of Park does two things. It locks the doors and it activates the seat belt alert. One of those computer modules is the likely culprit is what I am thinking. We'll see how the installer does for figuring it out. I figured someone here had run into the same experience but I guess not. When I do get a definitive answer next Friday (which is when the fix will be attempted), I'll post up about how it turned out.

Rick

 

[1991Brougham 10+ year member]

Here's how the story ended. The original noise on a scale of 1 to 100 would have been a 20. A Noise filter was installed close to the amp. That brought the noise down to a 1. Any sort of volume increase above none made it unhearable. Case closed!

Rick

 

[Sleeklsc 5,000+ posts]

That car fwd, rwd, or awd? Where are your power and RCA wires ran? Anything close to moving parts?

Srsly?

 

[jrdnhsnbrg 10+ year member]

Srsly?

How the hell am I supposed to know? My car is FWD and the only difference from the town car is it's just a tad smaller, lighter, and looks different

 

[Sleeklsc 5,000+ posts]

How the hell am I supposed to know? My car is FWD and the only difference from the town car is it's just a tad smaller, lighter, and looks different

And the fact that a vic, marquis and tc are all body on frame......and rwd. What got me the most was that you listed awd. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[basswiigee]

sounds like a ground issue....

 

[jrdnhsnbrg 10+ year member]

And the fact that a vic, marquis and tc are all body on frame......and rwd. What got me the most was that you listed awd. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Don't make me start a thread in MAF... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Sleeklsc 5,000+ posts]

Don't make me start a thread in MAF... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Please do, I'd be honored.//content.invisioncic.com/y282845/emoticons/blush.gif.99bc659ee2012b7d826165e26fb5eebe.gif