jdelanjo

Here is an odd but more than irritating situation that occurs into situations I have found so far. This happened with my 2007 HHR and now with my 2010 HHR.

first scenario. As neither hhr has a u_s_b port I purchased a adapter that plugs into the cigarette lighter that then converts to 2 usb ports so that I can charge devices. If that device is also connected using the auxiliary port for the stereo and the usb port in the cigarette lighter I hear whining noise coming thru the speakers when playing audio in aux mode. It does not matter what device i use. I have switched out usb and audio cords with no change. So if i want clear audio without the whining noise. I cannot charge the device. This happens only when engine running.

Second scenario. I have a PA system that I installed on the 2007 HHR. It is fully self contained. The speaker is pvc. Only 2 wires for power and ground are needed. Iconnected the power to the positive pole under the hood and the ground at the ground noted by the strut near fusebox. All works fine unless the engine is running. A whining noise came through the pa speaker. I changed the ground to several other body/frame areas, ran a direct line from the battery, and spliced into other power sources with no success.

Help!

Oldblue

Welcome to the site! Common electrical whining most likely from the alternator

jdelanjo

Thank you for the welcome and info..........

That these issues were experienced both on a brand new purchase of my then 2007 HHR and again with a pre-owned 2010 HHR I wouldn't imagine that there was an alternator issue with both vehicles.

Let's say that it is being caused by the alternator. What are the troubleshooting steps and corrective actions to be taken to stop it from happening?

donbrew

Usually a choke or a capacitor will help.

It's not an HHR problem it's a mobile electronics problem.

Grizzly old man

I used to sell CB radios in the day. I also installed them in cars for folks. It was very common to have a whining sound come from the CB while driving.

The simple cure was to put a fairly large electrolytic capacitor in parallel with the 12V line. A more effective way to do it was to use a transformer as a choke. You would run your 12V straight through the primary winding then just ground both leads from the secondary.

This caused the transformer to work as a choke.

It would take some extra hardware to be able to use your cigarette lighter/power outlet socket, like an extra cigarette lighter plug some wire and another cigarette lighter socket and a small transformer. Putting all this in some kind of metal box and hiding it under your dash would be somewhat challenging since there isn't much for space to put things under your dash these days.
You could put it out in the engine bay somewhere but then you would really need to use coax to run the B+ to the inside of the car. By using shield wire you shouldn't pickup any 'stray' noises to feed into your devices.

I used to get the small 110/12V step down transformers form Radio Shack and put them in small steel project boxes that the Shack also sold to build these. I know Radio Shack stopped selling the project boxes years ago.

With the low current your devices would need you might be able to use a small audio transformer then bridge a small electrolytic cap between the 12V+ and ground. Mind the polarity marked on the cap or it will blow up.

Here is a link to what might work for you but it is somewhat different than what I used to use.

http://en.wikipedia.org/wiki/Choke_(electronics)

Oldblue

I typed from the alternator, not faulty alternator.
As writen a choke is required to correct the whine, any audio shop should be able to help you

K8inHHR

donbrew was correct this is a common audio electrical problem, not a car problem.
I overcome this by making sure the audio device (my phone) is jacked up to the highest output volume possible and then using the car stereo amplifier minimally to increase volume.
Mostly drowns out the whine that way.

it’s because the stereo amplifier is picking up the incoming power surge as an electrical signal and translating that into the whine you hear. It happens in audio equipment and is something sound technicians at gigs/studios/etc regularly have to solve for.

donbrew

I think in this particular instance (from 2015) the problem was the ground wires doing what they are designed to do. The effect of plugging a device into 2 different ground sources causes a phasing problem. He probably didn't think that the cigarette lighter is grounded and one of the leads in the aux is ground.

Bonez

You either need to crank the stereo up or kick that passenger out.