2012 XLT (not Sony) whining in only one door speaker.

[Airmen]

I recently purchased a 2012 Explorer and had no sound from the right front door speakers. After removing the door panel I saw that someone had unplugged the speakers. I plugged them in and discovered that they have a whining sound. Here is what I have done so far.
I have added two good solid grounds to the amp chassis, no change. Whining with truck running or not or stereo on or off? With truck running it has the added whine if the ignition system along with the original whine. Any ideas welcome. Thank you.

 

[Rick]

I'm watching this thread. I would like to know what causes the whine when the stereo is off. That is definitely an odd one!

 

[peterk9]

Welcome to the Forum Airmen.
I'm sure that there would be many of us interested in the outcome of this issue.

Peter

 

[jmr061]

You may want to try a replacement ACM.

 

[Airmen]

You may want to try a replacement ACM.

You may want to try a replacement ACM.

Hello and thank you for the suggestion. I’m not sure what the ACM is?

 

[jmr061]

Hello and thank you for the suggestion. I’m not sure what the ACM is?

Audio Control Module - ie the radio

 

[Mr. Alligator]

It has to be a radio problem. The radio still holds power even when “off.” Odd problem, but same solution ... replace the radio. (If that does not work, you might need a Priest.)

Good luck.

 

[Gerry1]

Does the right door speaker play the audio source ALONG with the whine when powered on OR just whines when playng an audio source when on?
Does the rear right speaker play normally?

 

[Airmen]

Does the right door speaker play the audio source ALONG with the whine when powered on OR just whines when playng an audio source when on?
Does the rear right speaker play normally?

Yes you can hear music in the speaker along with the whine and the ignition going up or down when running. The right rear speaker works great with no whine or ignition sound.

 

[Airmen]

It has to be a radio problem. The radio still holds power even when “off.” Odd problem, but same solution ... replace the radio. (If that does not work, you might need a Priest.)

Good luck.

Thank you for the advise. It seams like a big job and costly to change but I need to keep troubleshooting and figure this out. Again, thank you! I will get some Holy Water on stand by in my tool box.

 

[Gerry1]

Yes you can hear music in the speaker along with the wine and the ignition going up or down when running. The right rear speaker works great with no wine or ignition sound.

So the front right speaker whines but plays audio source without distortion? So I take it you hear the whine with the volume all the way down but do lose the audio source completely when the volume is turned completely down? If thats the case the issue would point to a right front amplifier issue. Did you sub out the speakers completely at the door ( eliminating any tweeter crossover) to rule out some odd issue with the capacitor used to filter just the highs to the tweeter. My thinking is the amp still has power but has a problem with the one channel. If you know where the amp is, while the stereo is playing tap the amplifier cabinet lightly with a screwdriver handle to see if there may be a poor connection causing it.
My background is tv/ audio repair, so you got my brain going here.

 

[J_C]

This seems most likely to be a bad transistor in the radio, or more specifically that transistor may be integrated into an amp IC chip. If they go bad, they can leak and produce noise as long as there is input power present.

If you want to bother, you could set up a test jig outside the vehicle with 12V input on the two relevant supply wires and disassembled, trace the circuit with a multimeter on low voltage AC mode, with the radio off you can find where the signal originates, for example if starting at the output pin of an amp IC but there is no signal present on the input pin, obviously it is leaking. Same for a discrete transistor, you have 3 pins for signal in, signal out, and power in.

If you're not accustomed to doing electronics troubleshooting and repair then I'd check some junkyards for radios.

 

[Airmen]

This seems most likely to be a bad transistor in the radio, or more specifically that transistor may be integrated into an amp IC chip. If they go bad, they can leak and produce noise as long as there is input power present.

If you want to bother, you could set up a test jig outside the vehicle with 12V input on the two relevant supply wires and disassembled, trace the circuit with a multimeter on low voltage AC mode, with the radio off you can find where the signal originates, for example if starting at the output pin of an amp IC but there is no signal present on the input pin, obviously it is leaking. Same for a discrete transistor, you have 3 pins for signal in, signal out, and power in.

If you're not accustomed to doing electronics troubleshooting and repair then I'd check some junkyards for radios.

That is a great idea for troubleshooting. Thank you for the details. I do enjoy troubleshooting and am going to set up a test set for the amp and the outputs because it is easy to get to. Next will be the radio. I still am thinking its a ground allowing the wine and ignition feedback? I will report back by mid week. Again, thank you for your guidance.

 

[J_C]

It's not a ground if it only happens on that one channel. I could be wrong, I meant if you have checked that and made sure it has a good ground. Otherwise, that would affect all equally, would be a speaker ground local issue not an amp ground issue. If a fault caused significant DC offset on that channel, you might also need a new speaker.

Multimeter again, you can measure DC offset, there should be no DC going to the speakers, beyond a few mA at most, and since this is not a true audiophile setup, there should be zero DC offset going through it because it has the (typical) coupling capacitor, but I'd need more info to be 100% about that.

 

[Airmen]

It's not a ground if it only happens on that one channel. I could be wrong, I meant if you have checked that and made sure it has a good ground. Otherwise, that would affect all equally, would be a speaker ground local issue not an amp ground issue. If a fault caused significant DC offset on that channel, you might also need a new speaker.

Multimeter again, you can measure DC offset, there should be no DC going to the speakers, beyond a few mA at most, and since this is not a true audiophile setup, there should be zero DC offset going through it because it has the (typical) coupling capacitor, but I'd need more info to be 100% about that.

Thats is great process to check. I will tonight when I get home from work. During the week it gets tough to get far in troubleshooting.
I really appreciate the ideas.
thank you

 

[Mountaineer**06]

Another quick (relative term) check would be to disconnect both front speakers and using jumper wires, connect the left leads to the right speaker, and vise-versa, or remove and switch speakers. If the whine stays in the same speaker, the speaker is at fault. If the whine switches to the left speaker, then the radio (leaky IC, bad capacitor etc. as mentioned above) or interconnecting speaker wires (frayed wire insulation, touching ground, etc.) are bad.