Car Audio Question

**Hutch** · 11-01-2007, 09:51 PM

'97 4Runner. About a year and a half ago I replaced the stock head unit with an Alpine CD player, front speakers and added an XM Skyfi.

Not long ago I noticed that I can hear the revs of the engine through the speakers. It gets louder with high RPMs. It doesn't drown out the music, but it is noticable.

If it matters, the antenna on this truck is broken off so the regular radio doesn't work. And it's a manual. Oh, and it's green.

So how should I troubleshoot this?

**dfinn** · 11-01-2007, 09:54 PM

http://answers.yahoo.com/question/in...6084843AArykfU

**KnumbChucK** · 11-01-2007, 09:57 PM

Random guess. Make sure the electrical system is grounded right. I know in my truck the ground strap burnt up and the stereo became the ground.

**Hutch** · 11-01-2007, 10:14 PM

Well, tomorrow I will figure out whether it happens with a CD or just with the XM through AUX.

As for making sure the electrical system is grounded right, I have no idea how to do that. Should I wear shoes or stand in a bucket of water while I start grabbing wires under the hood?

**OldSchool1080s** · 11-01-2007, 10:22 PM

I'm not positive if it is similar in anyway, but when I installed my amp and sub, I had to run the RCA cords down one side panel along the car to the back and the power and ground cables down the opposite side panel to the back where the amp was. If these cables are too close together, you can get a hum sound that distorts the music. So maybe make sure that the 12V power cord going to the head unit as part of the wiring harness is pulled as far away from the actual audio cables as possible. I am not sure if this will help but figured I'd throw in my .02

**KnumbChucK** · 11-01-2007, 10:27 PM

Originally Posted by Hutch

As for making sure the electrical system is grounded right, I have no idea how to do that. Should I wear shoes or stand in a bucket of water while I start grabbing wires under the hood?

Not real car smart myself, but my ground wire ran from my engine block to the firewall. But that's an old jeep, so maybe electricity has changed since then

advres · 11-02-2007, 01:11 AM

Can't help you much but NEVER run audio cables parallel with electrical cables. To diminish distortion (ie interfernce) they need to cross at a 90 degree angle.

**Crass3000** · 11-02-2007, 05:28 AM

Yah I'm pretty sure this is a ground issue.

Edit: Like everybody else said it is best to run signal cables on a different side than the power but your never going to notice the difference unless you have some competition car audio system that draws tons of power.

**Skidog** · 11-02-2007, 08:51 AM

Ground wire..

M

**El Chupacabra** · 11-02-2007, 09:35 AM

If that vehicle has spark plug wires (vs. direct coil-on-plug style) -- when was the last time (if ever) that the wires were replaced?

I helped fix this problem on an older Jeep Cherokee, where the insulation on the wires had gone bad with age. New wires = smoother running, and the weird radio interference stopped.

**Buzzworthy** · 11-02-2007, 01:46 PM

Originally Posted by Hutch

'97 4Runner. About a year and a half ago I replaced the stock head unit with an Alpine CD player, front speakers and added an XM Skyfi.

Not long ago I noticed that I can hear the revs of the engine through the speakers. It gets louder with high RPMs. It doesn't drown out the music, but it is noticable.

If it matters, the antenna on this truck is broken off so the regular radio doesn't work. And it's a manual. Oh, and it's green.

So how should I troubleshoot this?

Hey, it is the wife's car, make her fix it!!