Thread: All of a sudden a whining noise when the car is running

Today while checking my amps to see if a cable was loose i accidently let the Line in cables touch the speaker wires, got a loud distotion, now I hear the engine whine when the motor is running. What should I check out?

what kind of whine is it the alternator can make noises like that and because you get current drawn from the battery and batteery to the alternator it could have effected that. alternators have been known to make all kinda of different sounds mistaked for other things.

is there any specific direction the noise comes from on the engine

It is a whine thru the speakers. No matter what the volume, it is the same level. It does not go up or down. You can hear the whine increase when the rpms go up. I have a two channel amp and a 4 channel amp. I just swapped amps and the noise is still there. So it is either in the radio or one of the RCA cables have shorted and have a bad ground. I am pulling each channel off one by one to see if it goes away. I will also move the power away from the RCA (I doubt that is the problem as I never heard it before today). If the AUX is on and no signal is going thru I hear it. CD on I hear it. Radio on it is like an AM signal that is weak or when you go thru the city and pick up electrical interferrence.

If you have the power wire running the length of the car with the RCA's that is not good. Keep them separated as much as possible. To get rid of your whine ground the shielding of the RCA. When you touched wires i assume the ground plane was damaged in the deck thus causing then noise.

Ok. I switch Top A Bottom A (Thats how I have the cables labeled) to Top B and Bottom B. Top B and Bottom B are where it is most noticable. . If I plug both Top B and Bottom B or Top A and Bottom A into A it is not as noticable. So is it safe to say it is the AMP?

Actually I was wrong. It is happening with either plugged in. I had the wires crossed. Wait a second....idea.

Bad cables?

bad cables or damaged pre amp on the head unit. This is what I would do. run a rca cable out side of the car and to the amp. if the noise goes away then you either have a bad patch cable or where your cable is run is picking up a radiated signal. If the noise does not go away then the pre amp on the head unit might be bad or you have a ground issue with the head unit. Did you run a signal source ground?

Signal Source Ground? I am not sure. This problem "just happened" when two the RCA came in contact with the speaker wires on the AMP.

The Amps are grounded to the trunk.
This is what I did.
I ran a cheap radioshack RCA from the Amps thru the middle of the car. I ran it on front channel on the radio only and it went away. Put it on rear and it came back. Aww damn. So I try to reproduce the sound to my neighbor who came by to hang, and now the front channel is making the whine.

I took the RCA and put it on my 2 channel that runs my subs and it made the whine. That eliminated my AMPS, I think. (The 2 channel takes signal off the 4 channel)





Ran it seperate from the power line.

you grounded the pre amp in the head unit through the rca's when you touched the speaker out puts. In short you need a new a head unit. a signal source ground is when you run a ground from the head unit to the grounding point for the amps.