• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-

Annoying whine in speakers with engine rpm

  • Thread starter Thread starter Danny2v
  • Start date Start date Jul 7, 2019
D

Danny2v

Member
Jun 24, 2019
57
2
8
California
Jul 7, 2019
#1
  • Jul 7, 2019
  • #1
Hey everyone, I've had a touchscreen head unit installed for a while and I have yet to figure out why I get a very annoying whine in my speakers that varies with engine rpm. Of the volume is set to 0, it's gone, the second it's at 1, it's audible. I've heard it could be a ground so I cut the ground wire on the head unit and grounded it straight to the frame of the car with no help. One thing I think I've read is it's possible it might be the alternator as I do know my alternator isnt working the best as the diode drains battery if the car sits for over 5 or so days. Could it possibly be that? Thank you
 

a91what

SendMeUrDataLog
10 Year Member
Apr 6, 2011
10,739
6,721
214
Hillsborough county
Jul 7, 2019
#2
  • Jul 7, 2019
  • #2
The easiest way to fix this problem is with a quality ground loop isolator. They do not always work however
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jul 7, 2019
#3
  • Jul 7, 2019
  • #3
IMO it could be an alternator issue. Excessive AC ripple is well known to cause electrical interference. Don't cut corners here.

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...
www.stangnet.com

Double check that all car frame and radiator core support ground spots are clean, bright, shinny, and tight. Double check that the left hand motor mount to frame rail grounding strap is in place.

Also check the ignition capacitors
 
Last edited: Jul 7, 2019
D

Danny2v

Member
Jun 24, 2019
57
2
8
California
Jul 7, 2019
#4
  • Jul 7, 2019
  • #4
wmburns said:
IMO it could be an alternator issue. Excessive AC ripple is well known to cause electrical interference. Don't cut corners here.

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...
www.stangnet.com

Double check that all car frame and radiator core support ground spots are clean, bright, shinny, and tight. Double check that the left hand motor mount to frame rail grounding strap is in place.

Also check the ignition capacitors
Click to expand...
Hmm now that I think of it, the radiator ground spot is far from shinny, I know the engine ground strap is perfect as I replaced that with brand new 4 gauge wire and crimps when I did my engine rebuild. Might give cleaning that grind a try though
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jul 7, 2019
#5
  • Jul 7, 2019
  • #5
I'm a big believer in Occam's Razor. I honestly think that the best use of your time is towards the known alternator problem.

Followed by the ignition capacitors.

Don't get me wrong. I still feel good grounds are important but for YOU the alternator should be at the top of the list.
 
D

Danny2v

Member
Jun 24, 2019
57
2
8
California
Jul 7, 2019
#6
  • Jul 7, 2019
  • #6
wmburns said:
I'm a big believer in Occam's Razor. I honestly think that the best use of your time is towards the known alternator problem.
Click to expand...
Do you think I would need to completely change it? Or do you think a alternator rebuild kit of American muscle would work? It includes the diode and bearings. Heres the link https://www.americanmuscle.com/paperformance-6gb-repair-kit.html
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jul 7, 2019
#7
  • Jul 7, 2019
  • #7
Did you read all of the information already provided previously in the "Howto perform charging system voltage drop test"? There;s information about rebuilding your own alternator verses replacing and my experience with the process. Hint. IMO it's not for everyone.

OBTW, IF it's a bad diode the linked rebuild kit will not fix your problem. Why? Because it does not include replacement diodes.

Some of the kits I have tried do include new diodes.
 
You must log in or register to reply here.

Similar threads

SN95 Desktop 363 Engine Combination - Looking for input
  • WhiteCobra95
  • Sep 8, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
11
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 6, 2025
Habu135
A
Resolved 03 GT Parasitic Draw Fuse 26 (PCM)
  • Antrix
  • Mar 22, 2025
  • SN95 4.6L Mustang Tech
Replies
2
Views
747
SN95 4.6L Mustang Tech Mar 24, 2025
89ripper
J
Car Diagnosis
  • j.2016
  • Aug 31, 2025
  • 2015 - 2023 (S550) Mustang -General/Talk
Replies
3
Views
336
2015 - 2023 (S550) Mustang -General/Talk Aug 31, 2025
Noobz347
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
  • Sufarry
  • Nov 6, 2025
  • Fox 5.0 Mustang Tech
Replies
12
Views
883
Fox 5.0 Mustang Tech Nov 9, 2025
Mustang5L5
03 Gt battery issues while driving
  • ThatBlack4.6
  • Nov 17, 2023
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
3
Views
2K
1996 - 2004 SN95 Mustang -General/Talk- Dec 1, 2023
Mustang5L5
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?