Question about 2002 GMC Sierra 1500

1 Answer

Alternator feeding back through speakers

From boats82373, You mentioned a bad ground. Would that be in the alternator, the radio, or elsewhere? Both the alternator and radio work fine now. Is it possible for the speaker wires to be grounded against the inside of the door? I ask this because the noise is only coming from the right side front speakers.
Any more info you can give me would be greatly appreciated.

Posted by on

  • Bruce Ekstrand May 11, 2010

    I do not know your original problem, but a grounded speaker wire would give this symptom. If the radio seems to be getting overly warm/hot, a grounded wire is almost a certainty.



1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert who has answered 20 questions.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

  • Contributor
  • 30 Answers

It could either be the ground or the speaker is about to go. Play the radio with the car off and see what you hear. If you still hear the static then try tighting all the connection on the alternator. Even check your battery terminals make sure cabaes are tight. Static is hard to pin point but its almost always just a loose connection somewhere. hope this helps

Posted on Sep 21, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

What does static in speakers mean?

Put an oscilloscope on the Generator (Alternator)
& look for A/C Ripple

Failed Diodes & a/c riding on the dc current

You have to check all vehicle grounds,That could
take half a day

Pull fuses you don't need to use the radio

Try the radio without the motor running (no alternator)

Their may be a bad diode in the A/C wiring, near the compressor
Try without the air on

Aug 12, 2014 | Cars & Trucks

2 Answers

I have a vm9114 Jensen in dash and I'm getting a lot of static From the radio station I've tried new radios different antennas and still have this problem what could it be

Static in radios especially if the static varies with RPM.s is a sign that there is a sparking action going on in the electrical system. This can generally be traced back to an alternator that has pitted slip rings and dirty brushes.. Normally it can be fixed by reconditioning the alternator or having an accredited auto electrician attach a small capacitor to the alternator ( Bat terminal for the lead ) with the capacitor bolted to an earth point . Seek advice from the electrician and radio fitting shops .

Feb 18, 2014 | Cars & Trucks

1 Answer

Airplane sound comes from car audio system speakers only when I turn the radio on.

this sounds like you may have a bad alternator or radio was install wrong.the alternator has a built in condensor to stop the back feed into radio,

I would make sure the radio is installed correctly first, all it takes is a wrong wire in the wrong spot to cause this type of problem, another thing that causes this is if you have an amp connected, the amp must be wired correctly, make sure there is a good ground a soild ground close to amp and power is coming from battery to feed amp and not from fuse box.

Dec 23, 2012 | Cars & Trucks

1 Answer

The check charging system comes on with a red battery


Aug 06, 2011 | 2005 Mercury Montego

2 Answers

Would a bad fuse cause a head light to burn out? I've replaced my right head light twice in two months on a 2000 Daewoo Lanos S and don't know what could be causing it. I also get a terrible buzzing...

sounds like a ground problem. sorry i have no clue where to look and this would be hard to find. the ground will feed back and cause the noise. a fuse will have nothing to do with it. fuse just works until current gets too high and it burns to stop a short from burning wires and possibly the car. is the light flickering at all. what burns out a lamp quick is a lot of off and on that moves the filament and i wears out. if ther is a bad ground to that light it is losing the power then getting power then losing it again. see what i mean. and this action cause noise in the ground of the car which shows up on the radio speakers. good luck

May 22, 2010 | 2000 Daewoo Lanos

1 Answer

I think my alternator is bad would this also

NO. The alternator feeds the battery, not your cars systems. The car systems are powered by the battery and the battery is constantly charged by the alternator. If your radio doesn't have power, check the fuse first, then the hot lead to the radio with a test light do not ry to "spark" the wire to test for power as this will blow the fuse. A radio fuse is only a 5 or 10 amp fuse and is very easy to blow out.. If the radio is getting power then the radio has to be replaced

Mar 22, 2010 | 2000 Ford Escort

1 Answer

Low voltage

what is the condition of the battery cables you are probably onto something about a ground but i dont think your ground issue is going to be at the batteries you may not have a good ground on the alternator. The next thing I would check is ... the alternator itself do you know that you are getting between 13.6 and 14.2 volts out of the alternator, a under charge or a overcharge condition both are bad for batteries.

I would check alternator output first if it is not within the above range you need to replace it

If the alternator is putting out in the range of 13.6 to 14.2 then you need to look elsewhere... you may have something draing the batteries overtime interior lights, electric brake controller for trailor brakes if equipped sound system if anything is getting power without going through a switched circuit this could also be your cause.

hope this helps

Aug 23, 2009 | 2002 Ford E350

2 Answers

Motor noise coming out of speakers

you may have a short in one of your speaker wires, or your antania

Aug 07, 2009 | 1993 Buick Century

1 Answer

Alternator Feedback through speakers

What kind of feed back ? Does it get louder with RPM . Ignition system can also cause this . But just to be sure have the alternator check for ac voltage ripple .

Ripple voltage is when the DC voltage varies between (for example)12.5 Volts and 13.5 Volts, and does so rapidly. Technically, an alternator produces "alternating current", (hence the name, 'Alternator') and that AC voltage is converted to DC by running the current through a bank of "diodes". Alternator Diode Check and AC Ripple Check

Oct 05, 2017 | 2002 GMC Sierra 1500

2 Answers

Wont hold charge in expedition

  1. Check the wiring of the new radio installed as follows..
  2. Disconnect battery ground
  3. verify radio ground wire is grounded to metal
  4. verify radio hot wire (normally red and thick) is connected to a power source that is off when the ignition key is in the "off" position.
  5. verify that the always hot wire is connect to a constant 12v power supply even with the ignition off.
  6. make sure the pwr antenna wire if not used is taped at the tip and not touching any metal.
  7. verify that all speaker wires are connect correctly and not shorted to ground.
  8. connect battery ground you may get a small spark if your courtesy lites work.
  9. start engine verify your battery is charging by disconnecting the battery ground cable while the engine is running, it should continue running if it don't, alternator maybe bad.
  10. If it continues running problem solved..

Nov 11, 2008 | 1987 Ford F 350

Not finding what you are looking for?
Cars & Trucks Logo

198 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

79865 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides