Diagnosing an odd sound.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Diagnosing an odd sound.
It's interesting. It sounds a lot like RFI except the head unit and amp are powered off. The whine sounds JUST like RFI, and even coincided with engine RPM.
I checked the carb and it's securely mated to the manifold so I'm not hearing the whistle of the engine vacuum...at least not from there.
I sprayed some carb cleaner at some of the exposed vacuum tubes and no change in RPM occurred.
I'm really curious, since the sound seems to be coming from the cabin, and either it's not coming from the engine or I just can't hear it over the engine and exhaust.
Who's got an idea on this one?
I checked the carb and it's securely mated to the manifold so I'm not hearing the whistle of the engine vacuum...at least not from there.
I sprayed some carb cleaner at some of the exposed vacuum tubes and no change in RPM occurred.
I'm really curious, since the sound seems to be coming from the cabin, and either it's not coming from the engine or I just can't hear it over the engine and exhaust.
Who's got an idea on this one?
Melting Slicks
Joined: Sep 2005
Posts: 2,720
Likes: 906
From: Warminster PA
Whine coming through the speakers is RFI. Eventhough you may not have the system turned on, there are circuits inside that remain powered and can be affected by alternator whine.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Whine coming through the speakers is RFI. Eventhough you may not have the system turned on, there are circuits inside that remain powered and can be affected by alternator whine.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
This was also my first thought but the speakers are connected to only the amp. The head unit's amp is not even on, it's switched off.
While the engine was running I tested the terminals on the amp for the speakers and sub. All were 0.00 and the amp was shut down and cold.
The sound does not get louder the closer I get my ears to the speaker. It's such an odd sound.
I have a filter and may try it inline with the alt just for giggles but I doubt it is really RFI.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Well I just installed the console so the vacuum lines were firmly in place on the HVAC control. I can check the line as the heater box tomorrow.
I'll also remove the fuses from the amp to check that part again.
Premium Supporting Vendor
Joined: May 2000
Posts: 4,312
Likes: 70
From: Clearwater FL
Whine coming through the speakers is RFI. Eventhough you may not have the system turned on, there are circuits inside that remain powered and can be affected by alternator whine.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
Get a filter and put it in the alternator positive lead, this should make the whine go away. Also make sure all of your ground connections are good.
Make sure the ground is good.
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Thread Starter
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From: Columbia Missouri
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From: Columbia Missouri
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St. Jude Donor '07
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From: Fishers IN
You can buy them with gears that give off a whining sound...something like a supercharger. Some people like that sound.
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From: SoCal
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From: Orange Park Florida
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....