I'm working on my brother's car for him and have ran into a problem.

2006 HHR. 112K miles.

He's getting the "check charging system" error. 6 weeks ago he got this error and had a shop check it out. They diagnosed bad battery and replaced it. He's been running trouble free since then. up until yesterday, anyway. now the light's back on and the shop diagnosed bad alternator. I replaced the alternator for him. While replacing the alternator, i pulled the battery and had it tested as well, just in case. battery checked out good, but just a hair low on charge (just under 12 volts).

once the alternator and battery were back in I had him start the car up and let it run a bit to make sure everything was in working order. it idled in the driveway for 5 mins or so and all was well so we went to take it around the block. as soon as we left the driveway the battery light came on, but no text popped up on the display. i thought perhaps it was the old error code that hadn't been cleared yet but, just in case, we went back to the house and shut the car off. i just wanted to make sure that it would start back up. cranked back up just fine. left the house again and made it a block and the "battery saver" info popped up and all of a sudden accessories were shutting off. we turned around and made it just into the driveway before the car died. i know it won't fully charge the battery in such a short amount of time, but i can't imagine it would kill the car right away either.

so pulled the battery and threw it on a charger. now, since i'm waiting anyway i'm here trying to figure out what else to do with the thing to keep my brother from having to go to a shop to have it fixed. Anyone have any ideas? the car makes no telltale noises and i am scratching my head here.

so far we have done the following:

replaced battery
replaced alternator
checked belt
checked for loose connections at battery and alternator

what else goes wrong on these things? i did some searching but it seemed like everyone's issue was solved with either a battery, belt, or alternator. these three items are in good shape.

Thanks
Chris

 

You need to test the charging system output 1st.
In other words, stick a meter on it while it's running and see what the output is. Should be done with a charged up battery installed.
Trying to guess at the problem without some output numbers would be just that. A wild guess.

Fwiw. "but just a hair low on charge (just under 12 volts)". No. That's more than a hair low.
A fully charged battery should be in the 12.7- 13.0 volt range.

 

Be absolutely sure that ALL ground are good.

The wires in the alternator connector have always worried me, they look like they are asking to get frayed.

 

Make sure your belt is in good shape and not slipping. Do a very close inspection of the battery cables. Lift, clean and replace all battery cable connections and replace any that are questionable. Don't forget, they are about 10 years old. With the car running, check the voltage at the battery. It should be between 13.5 and 14.5 or so. Just because the battery is new does not mean it's good. I went thru a rash of bad batteries, just bad luck. Same goes for the alternator, could have a bad ground or loose connection and may have blown just one diode so the alternator sorta puts out but just can't keep up. Last, and the hardest to find is a ground in the system. Turn EVERYTHING off including dome lights. Disconnect the neg. battery terminal and jump a test light between the cable and neg. post. The light should be dim but if it's real bright you have a current draw. To find it, start pulling fuses and run the test until (hopefully) you find the grounded circuit. Good luck with your problem, today's cars can be electrical nightmares.

 

perhaps the battery was under charged and unable to support the immediate draw (starting a couple times, blower on high, a/c, steering, etc)?

i'm used to working on old carbureted stuff where all you really had to worry about was whether or not they'd still turn the motor over. i figured with as strong as it was turning over, it should have been good enough to go ahead and run it. perhaps not.

i'm finding out that even amongst newer cars, this one seems to be more electronically fickle than the rest that i have any experience with.



to the rest with suggestions of loose ground or whatnot: i'm finding that this vehicle is a bit off from most i've worked on, and my previous experience may not really be of that much help... so, the following question is an honest one: what's the likelyhood that something that I didn't mess with (a ground elsewhere in the system, for instance) would just all of a sudden fail? and do so in such a way that when a shop had it in, charged it up and ran a diagnostic check on it that they would come back and say that the only thing wrong with it is the alternator? i double checked the connections that we messed with and find them satisfactory. the connections at the alternator were in very good shape. the connections at the battery were tight and like-new.

The car was exhibiting no symptoms or problems prior to yesterday morning when, as though flipping a light switch, it died. in my previous experience bad grounds generally exhibit intermittent symptoms (at first anyway). for instance, with our '06 yukon, the rear locks and wiper would occasionally not work at idle, but would work as we would get onto the highway. is the HHR likely to do things in the same manner? or is there a known problematic connection that frequently fails all of a sudden?




I am charging the battery as we speak. I will wait until it is completely charged and then give things a try. if anything acts amiss, i will at the very least check the voltage at the battery and/or run to o'reilly's and have them run their charging system diagnostics.

thank you all for the help. i will post updates as things progress.

-Chris

 

The ground connections are kind of notorious!

The HHR electrical system takes the alternator concept to the max.
To over simplify:
The alternator really is a motor that needs a power source to function. If the battery is not "nominal" then the alternator will not work. Semantics may be incorrect but, I'm getting at the concept.

 

Thanks for the insight. I will fully charge the battery and report back.

i have to laugh a little. i've been battling GM and their faulty/fickle electrical systems for decades. i see not much has changed. Do HHR's have issues with the valve covers leaking oil too?

-Chris

 

Follow my post #2 above. The 1st two sentences.
Without knowing the output or charging status, you can guess and check all you want.
Just trying to help you do some diagnostics and not play a guessing game.

 

Fwiw. I'm an old school type guy too. Been working on automotive stuff for about 40 years.
The newer stuff is way more complex but the principles of the 12 volt negative ground system still apply.
I can still get out my 30+ year old Snap-On tester and check a modern day vehicles charging system. It's always the 1st task to do when having alternator or charging problems.

 

What I was getting at is that the battery is "exactly" good enough to drive the alternator. If it's not "nominal" the alternator will NOT work.

The old saw "the battery is only for starting" with an alternator, just does not really apply anymore. The battery is a vital part of the entire system. You cannot test the system by disconnecting the battery anymore! In fact, you cannot test the charging system without a good battery, and vicey versy.