Any car audio gurus out there?

[NightCrawler]

A while back I bought a XM unit for my truck. Its powered via the DC socket and is connected to my radio via the AUX input on the radio.

Well a few days ago I noticed a very loud and obnoxious whine coming through the speakers and the more I accelerated the louder it became. It was crystal clear when I first hooked it up and its now doing this without me touching a single wire.

I did a search online and found something called a Ground Loop Isolator CLICK ME!!! but I'm not 100% sure this would help.

My problem is it JUST started to do this, it hasn't done it since I bought it back in Feb. What can be the cause of this and how can it be fixed?

BTW, the XM unit is the Delphi RoadyXT. CLICK ME!!!

 

[omslaw]

The Ground-Loop Isolator will likely cure your issue. Try it - if it doesn't work, take it back. However, what you describe is classic ground-loop noise.

 

[NightCrawler]

I'm not doubting you, I'm just asking. What would cause it to start doing it when it never did it before?

 

[yamahor]

(NightCrawler @ Jul. 26 2007,00:28) I'm not doubting you, I'm just asking. What would cause it to start doing it when it never did it before?

It might not be the head unit itself needing the GLI, (shortened, like it? lol) It might be the XM unit. Plugging into the lighter socket like that has caused me some problems with stuff before...

 

[omslaw]

Hard to say what caused it to start all of a sudden. I usually need to keep a GLI installed inline with my amplifiers - otherwise the whine is unbearable.

 

[yamahor]

yep... I need to install one in my car... Have a NICE whine that gets LOUD at my "fun" driving times...

 

[NightCrawler]

Kool. Thanks fellas!

 

[heavybusa]

Pesky bad grounds.

Most times is corrosion on a connector somewhere.

 

[Projekt]

Do you have to place an antenna on the body with a cable going through a doorjamb or a hole in the firewall? If so it could be that the insulation on the cable is compromised and is contacting metal on the body...
Either that or your car's flux capacitor is about to fail..

 

[NearDeath]

I used to install professional systems in car audio...

#1 reason for engine noice is because someone ran the power cable alongside the RCA wires to the amp location.

#2 In your case, turn down the gains on the line converters that you used on your stock stereo. YOu probably have them a bit too high.

 

[buss05]

(Cloud9 @ Jul. 26 2007,09:42) I used to install professional systems in car audio...

#1 reason for engine noice is because someone ran the power cable alongside the RCA wires to the amp location.

#2 In your case, turn down the gains on the line converters that you used on your stock stereo. YOu probably have them a bit too high.

+1 on the installs. Used to install until I moved up to manager.

The most common problem I found was:

1. Poor grounding on the battery itself to the chassis
2. Poor grounding to the alternator
3. Corrosion
4. Poor grounding to the unit itself
5. Possible bad alternator or on it's way

Ground loop isolators are hit and miss.
Good Luck!

 

[buss05]

(Projekt @ Jul. 26 2007,06:25) Do you have to place an antenna on the body with a cable going through a doorjamb or a hole in the firewall? If so it could be that the insulation on the cable is compromised and is contacting metal on the body...
Either that or your car's flux capacitor is about to fail..

XM units are not like a regular radio. They do not get their ground from the antenna. If it was a compromise in the insulation, it would likely not work at all.

 

[ks-waterbug]

(omslaw @ Jul. 25 2007,23:18) The Ground-Loop Isolator will likely cure your issue.  Try it - if it doesn't work, take it back.  However, what you describe is classic ground-loop noise.

+1...

 

[NightCrawler]

(Cloud9 @ Jul. 26 2007,12:42) #2 In your case, turn down the gains on the line converters that you used on your stock stereo. YOu probably have them a bit too high.

I'm not sure what you mean by that. I just have the XM playing though my speakers via the AUX input on the radio. The jack is located on the front of the radio from factory. I just plug one end of the AUX cable to the XM unit and the other end straight to the radio.

I'm not getting the "gains on the line converters" part.

 

[OZZY]

ok, u do not have a line level converter. try upgrading to a better auxillary cable, something like monster or acoustic research. i have a pretty good feeling that a better AUX cable is gonna solve your problems.

 

[Vic_E55_2001]

(NightCrawler @ Jul. 26 2007,11:57)

(Cloud9 @ Jul. 26 2007,12:42) #2 In your case, turn down the gains on the line converters that you used on your stock stereo. YOu probably have them a bit too high.

I'm not sure what you mean by that. I just have the XM playing though my speakers via the AUX input on the radio. The jack is located on the front of the radio from factory. I just plug one end of the AUX cable to the XM unit and the other end straight to the radio.

I'm not getting the "gains on the line converters" part.

Roady has adjustable output, not just line level. You can turn it up or down in Roady menu.

 

[loboboy]

before you do anything do an OHM check on all of your spark plug wires. If it did not make the noise before and jsut started then it leads me to think that you may have a leaking spark plug wire. If you pay close attention to the idling of the enigne I bet you have a slight miss in it.

if you want an even stranger issue I have a Duramax and all of a sudden one day i have a very annoying whine in my system. hell I don't have spark plugs, after a few days of testing crap I found that my Eclipse 4 channel amp went Tango Uniform on me and it was creating the noise internally. Replaced the amp under warranty and off I went noise free.
my point is don't install a GLI if you don't have to, look soemwhere else.
Also try and provide a different power source to the unit and see if it changes and if it does then you are getting some EMI(electromagnetic interference) from somewhere upstream of the cig lighter.
hope these ideas help.

 

[rubbersidedown]

Powering audio devices thru the cig lighter is never a good idea. I would wire it directly to the battery (with an in-line fuse of course). Now your DC power source will be from the vehicles primary electrical source and not a sub system with noise potential.

I'd start there. RSD.

 

[BlkDrgnZ28]

its the cig plug because i had the same problem when i had my ipod hooked up with a radio signal transmitter that was powered by the cig plug if i paused a song and turned the volume up it souned like a supercharger but super high pitched you could wire directly off of the batery and hook up a relay off of an ignition wire so you wouldn't hear the whine anymore and when you turned off the car you woulden't have to turn off your xm unit or you could buy a whole new head unit with the xm built in you'll just have to run a xm anteana like you probably already have and just transfer service to your new unit and have a cd quality sound unless you have a direct plug into your car

 

[katman]

(loboboy @ Jul. 26 2007,16:03) before you do anything do an OHM check on all of your spark plug wires. If it did not make the noise before and jsut started then it leads me to think that you may have a leaking spark plug wire. If you pay close attention to the idling of the enigne I bet you have a slight miss in it.

if you want an even stranger issue I have a Duramax and all of a sudden one day i have a very annoying whine in my system. hell I don't have spark plugs, after a few days of testing crap I found that my Eclipse 4 channel amp went Tango Uniform on me and it was creating the noise internally. Replaced the amp under warranty and off I went noise free.
my point is don't install a GLI if you don't have to, look soemwhere else.
Also try and provide a different power source to the unit and see if it changes and if it does then you are getting some EMI(electromagnetic interference) from somewhere upstream of the cig lighter.
hope these ideas help.

+1 on spark plug wire if you never had it befor check there first.