Riktar

As a preface to this story, over the last 2 days the HHR was developing a whining noise which was barely audible but noticeable when you listened for it with the radio off. And the noise followed the speed of the engine as the revs went up and down, even when sitting still.

The battery in my HHR was replaced 3 months ago so when the car didn't want to start because the battery didn't crank the engine much before going into a 'click, click, click' I was scratching my head since their was no idiot light popping on and the DIC was not displaying any charging/alternator messages. So I sat for 5 minutes with everything off and tried to do a quick key turn start hoping the engine would crank just fast enough to maybe start. And I was lucky, it did.

The car was running just fine and no idiot light or messages were being displayed. While this could be a real head scratcher I looked down at the little add on I had installed because I wanted multiple USB charging ports:


This was with the car running and the auto lights off. Since this is a static image I will report that the voltage would fluctuate to almost 12 volts and go as low as 10.5 while I was driving home, which I (thankfully) got to without incident. Once I was home and parked in the driveway I shut the car off and went through the same issue I experienced earlier.

Now if I remember correctly, don't alternators have 3 'banks' that do the charging and if a diode pops on one of those 3 banks the alternator will only perform at 2/3 it's charging ability which (I think) would explain why the voltage was running between 10-5 - 12 volts when the car was running. I would hazard a guess that if this would have been winter and I would have had fans, blowing, seats heating and the defrosters turned on it would have been more than my sick alternator could have kept up with.

What is curious about this is why the system didn't show this? How low does the battery voltage have to get before the idiot light comes on or the DIC displays a warning?

When I put this little device in I thought the voltage display was cute but beyond that all I cared about was having the extra USB ports for charging. And since I know the system usually hovers between 14.3 and 14.8 volts when everything is running I am pretty sure a replacement/new alternator will solve my problem.

If anyone can confirm that I am on the right track or show me where I am mistaking a mistake (Wouldn't be the first time) in diagnosis I would appreciate it. I would also like to know why the system in the HHR didn't alert me to this problem.

RJ_RS_SS_350

In your 2007, it seems the charging idiot light is 2nd from the left, does the light momentarily come on when you turn the key on?

The whine would seem to Indicate a bad alternator, you could probably get it tested for free at the auto parts store.

Another potential cause of bad charging is a stretched Serpentine Belt or faulty tensioner. Or a bad battery.

Riktar

The belt is at proper tension and in good shape. And as I mentioned in my post the battery is only 3 months old. I suppose it could be the battery but why the sudden whining noise and I can't get the batt voltage above 12v?

All the idiots light do function. And yes you are correct, the charging/alternator/battery light is 2nd from the left. It goes out with the rest of the lights after 1 or 2 seconds.

firemangeorge

Take it and get the charging system checked. A system check will tell you all the outputs ( voltage, amps etc) Don’t depend on an idiot light to always warn you. They usually only light up if it’s a complete failure of the charging system.

sleeper

I test my battery voltage & load test battery, Alt @ idle, then run to 2K & see output bout every 2 years..

donbrew

The voltage output varies according to need, like socialism. Maximum of about 15 volts if you have everything on and the battery doesn't have enough power.
You best estimate of battery health is engine off battery voltage, it should always be above 12.5 volts. Could go low if battery is fully charged and low demand.
Most big box auto parts stores will diagnose the electrical system for free.
The whining sound could be a warning sign of the bearings wearing out or the belt wearing out or the belt idler wearing out, among other things.

Riktar

Well there is no question about the alternator now. I went to pull the car in the garage today and it was totally dead. No lights, no nothing. Went to put the charger on it and I could hear the spark as well as see the spark on the charger cable. Meter pinned, internal breaker on the charger tripped and that was that. Took the main lead off the alternator and wah-lah. The battery started accept a charge as it should. Pushed the car in the garage (I am really thankful that the HHR rolls so easily) and am going to leave the charger on for a bit before I disconnect the battery and then start changing the alternator.

Once this is done I will perform a further check to make sure I didn't bung-fu my 3 month old battery as well as see if there is any parasitic drain on the electrical that could be a problem.

Thanks everybody for all the suggestions and replies. Didn't get around to trying all of them since, well, the alternator went from weak to catastrophic failure/short internally.

fastsuv

Use a voltmeter at the battery terminal on the fuse box to a good ground point.

Don't do anything until you verify the reading on the digital meter/USB port unit that you installed. The readout could be bad and cause you to chase a non-problem.

Steve

Riktar

I did verify/compare the voltage at the engine fuse block points and the battery itself in the car and everything is within 0.02 volts. I would call that within acceptable margin of error for the usb accessory I installed.

But this thing is getting weirder. Since I did verify the alternator problem and the battery and serpentine belt are only 3 months old I got a reman alternator and installed. Everything was working as it should. Resting voltage was around 12.6v and was around 14.5 after starting the car.

Then late this morning, the batt idiot light came on. What?!?!? That wasn't even a problem before!

Battery voltage started moving up and down at random intervals. Keeping the RPM above 1500 seemed to keep the light off. I should note that once the volts started moving up and reading above 12.7v the batt light would go out. No pattern, no ability to make the system charge or not charge.

I know voltage regulators went from being external devices to internal works of the alternator. I thought I read somewhere that some systems use computer control nowadays. Not sure what that entails.

Lastly the car was down to 11.7volts when I pulled in the driveway a few minutes ago. After I shut off the motor and turned off the radio I could see the voltage starting to climb back up.

Any thoughts?

Oldblue

It is plausible the reman alternator is not functioning properly.