Diagnosing an odd sound.
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
Matt, bux to doughnutz you have a ground loop in the speakers....
wonder if the speakers themselves are grounded somehow, and you are having some alt induced whine as a result....what you need to is run it with engine off, and see if the noise persists....
alternator whine is nearly impossible to eliminate with certain, typically cheeeper, amps.....
you can do a L/C filter, you can try running it off the battery direct on positive and negative....disconnect the inputs with amp keyed ON, and see what you have.....ground loops in this about 1/2 way designed aftermarket crap are just that....crap.....
I been an old tyme ET for decades now....BTDT...and did engineering design work.....RFI and EMI are olde tyme enemies of mine....
from the 50's yet even....
wonder if the speakers themselves are grounded somehow, and you are having some alt induced whine as a result....what you need to is run it with engine off, and see if the noise persists....
alternator whine is nearly impossible to eliminate with certain, typically cheeeper, amps.....
you can do a L/C filter, you can try running it off the battery direct on positive and negative....disconnect the inputs with amp keyed ON, and see what you have.....ground loops in this about 1/2 way designed aftermarket crap are just that....crap.....
I been an old tyme ET for decades now....BTDT...and did engineering design work.....RFI and EMI are olde tyme enemies of mine....
from the 50's yet even....
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Okay, updates.
First, I'll say that the sound seems to be coming from the dash somewhere...maybe behind it but I can't figure out what might be making this whining. It sounds just like alternator whine, but I can't pinpoint it.
I pulled the fuses on the amp and for the head unit. Neither are getting power now and I checked all the speaker terminals again with a DMM and got 0.00 again. I'm fairly sure it's not the speakers since they only connect to the amp and it has no power.
I installed a noise filter on the positive wire to the alt's BAT terminal, and not only did the noise not change, but now the GEN lights flickers on and off no matter RPM. That one baffles me.
Did I put the filter on the wrong power wire? Should it be the power wire that goes into the alt via the CS plug instead of the BAT terminal wire from the harness?
This one is sure killing my head.
First, I'll say that the sound seems to be coming from the dash somewhere...maybe behind it but I can't figure out what might be making this whining. It sounds just like alternator whine, but I can't pinpoint it.
I pulled the fuses on the amp and for the head unit. Neither are getting power now and I checked all the speaker terminals again with a DMM and got 0.00 again. I'm fairly sure it's not the speakers since they only connect to the amp and it has no power.
I installed a noise filter on the positive wire to the alt's BAT terminal, and not only did the noise not change, but now the GEN lights flickers on and off no matter RPM. That one baffles me.
Did I put the filter on the wrong power wire? Should it be the power wire that goes into the alt via the CS plug instead of the BAT terminal wire from the harness?
This one is sure killing my head.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
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Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Okay, updates.
First, I'll say that the sound seems to be coming from the dash somewhere...maybe behind it but I can't figure out what might be making this whining. It sounds just like alternator whine, but I can't pinpoint it.
I pulled the fuses on the amp and for the head unit. Neither are getting power now and I checked all the speaker terminals again with a DMM and got 0.00 again. I'm fairly sure it's not the speakers since they only connect to the amp and it has no power.
I installed a noise filter on the positive wire to the alt's BAT terminal, and not only did the noise not change, but now the GEN lights flickers on and off no matter RPM. That one baffles me.
Did I put the filter on the wrong power wire? Should it be the power wire that goes into the alt via the CS plug instead of the BAT terminal wire from the harness?
This one is sure killing my head.
First, I'll say that the sound seems to be coming from the dash somewhere...maybe behind it but I can't figure out what might be making this whining. It sounds just like alternator whine, but I can't pinpoint it.
I pulled the fuses on the amp and for the head unit. Neither are getting power now and I checked all the speaker terminals again with a DMM and got 0.00 again. I'm fairly sure it's not the speakers since they only connect to the amp and it has no power.
I installed a noise filter on the positive wire to the alt's BAT terminal, and not only did the noise not change, but now the GEN lights flickers on and off no matter RPM. That one baffles me.
Did I put the filter on the wrong power wire? Should it be the power wire that goes into the alt via the CS plug instead of the BAT terminal wire from the harness?
This one is sure killing my head.
OK, sounds like your other thread lies there, I missread/interpreted what you maybe said there....that choke filter goes between the typical head end, NOT THE AMP, in the + wire to whatever 12 source you want....NOT directly to the alternator....leave ALL alt wiring alone...period, no matter what.....case closed, as I say....
the amp should go off a decently powerful point directly, through a fuse and say the horn relay or alt Bat term direct.....amp is typically switched on/off by a signal from head end.....head end has that choke filter in it.....everybody should be grounded to engine direct with a OMG cable...10 ga is nice, typically.....filter ground go to amp end of that wire.....
former comments apply...SOME amps just will not shut up....
you CAN try wiring it directly off the +12 of the battery, amp ONLY, and see if that cures it....you can pull the RCA input cables and see if that quiets it down....
alt whine is a bitch some days....only systems that don't have it are higher dollar...aftermarket that is....I know why, but ti's too crazy to explain....
Advanced
Joined: Jul 2007
Posts: 85
Likes: 0
From: east TN
Could it be the blower/fan motor whinning? Doesn't it run on low speed even when the heat or AC is off for air recirculation. I have had a leaf get in my fan blower and whine as it hits the side of the blower housing.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
That's funny.
I removed the blower altogether. No blower.Gene - This filter was designed specifically for the POS wire from the harness to an alternator. It's designed specifically for that wire, and even says right on it, for alternator POS lead.
The head unit is using stock harness wiring, meaning a constant hot and a switched 12V. The amp is powered and grounded at the battery. I'm guessing that would be the ground loop but the amp is not getting a signal. No RCAs and no fuses. 0.00 at each speaker terminal, and the amp is a VERY high quality company known for the great6 noise filtration.
I don't think it's a speaker making the noise.
Can the courtesy light timer relay thing make a sound other than it's designed to?
