Hello, my daily driver, a 2010 Chevy HHR Panel (not sure if LS or LT) just had a problem Wednesday. On the way to work, my red battery light suddenly came on, without warning, and within 30 miles the battery was completely discharged.

My wife managed to come get me, and give me a jumpstart, and we left it connected for a while. (based on where I was parked, we had to go direct from battery to battery.)

I made it home, pulled out my handy volt meter, and checked. Battery was reading less than 11 volts, so I as a precaution I changed it out (since it was 4 years old), but I knew it had to be something in the Alternator or charging system.

So, I brought it into my local shop, and they ran a quick check on it.

They got 12v on the battery terminals (low amps, and falling while it runs), but the front posts under the hood that you're supposed to use for jump starting show the 14.4 v. (the post and the nut)

At that point, they said it was beyond them, gotta find someone else. (they suspect something in the computers, and likely only dealership can fix it)

My local Chevy dealership used to be great but has really gone down hill lately so I'm hesitant to take it in to them for diag/repair, as I'm likely to get a couple thousand into it without a resolution.

I've heard about the wire (fusible link that's really just a 10ga wire?) coming off the alternator, but I haven't gone under it yet. Might give it a try this weekend.

I'm hoping one of you has heard of this, and might have an idea of what I can look for, or a possible solution to this. I have not checked fuses yet, and based on how little time the first shop spent on it, I'm pretty sure they took the 1 voltage measurement, and just stopped there without checking anything else. 14.4v? there's no problem, owner must be wrong.

Any help would be greatly appreciated. I've put 312,000+ miles on this little guy, and love it to death. Hoping I can keep him from the grim reaper's chop shop for a few more years.

 

The "Integral relay-regulator" has failed. It is located on the generator. In the place where the wires come out. At the same time, check the condition of the brushes (remove the generator anyway).
To be absolutely sure, test: in this state of affairs, the voltage of your CAR’s on-board network depends on the engine speed: the higher the speed, the higher the voltage.
But there is no need for fanaticism when checking, excessive excess can burn the microcircuits of various equipment.
The repair consists of the following: - remove the faulty “integral” from your generator and go to the store. There you buy exactly the same one, matching the letters and numbers written on the case. Put it in place of the old one. That's it!

 

Welcome to the site, replace the alternator, the belt and tensioner may also need to be replaced at that mileage.

 

It is not possible to have those readings.; unless the battery was checked engine off and underhood engine on and/or the terminal on the fuse box is very loose.. The post on the fuse box goes directly to the battery, same as reading the post at the battery.

The battery should not decrease with engine on, it should go up to whatever the alternator is producing above 12.7 The alternator should always be producing a minimum of 12.7.

Yes, the alternator seems to be bad or the belt is broken or connections loose. All are easily checked.

 

Well now wait, if there's 14.4 at the fuse block, but only 12 volts at the battery, shouldn't we suspect the cable between the 2? Broken battery terminal clamp,, loose or otherwise bad connection?

I agree that there may also be a problem with the alternator, belt, or fusible link.

 

So I checked it out myself, with a meter, and found that I've got 12 V at the battery AND at the post (which is what I would have expected.) when the motor was running. So either they didn't read it right, or it's an intermittent open, or something else, but I arranged to get it into another shop for diagnosis on Monday.

Thanks for all the suggestions guys. It wasn't adding up to me either.

 

If it was only 12v with engine running something is wrong with the alternator. The alternator should produce at least 12.7, sometimes as high as 15v.

 

The 14.x V must have been with the engine running. Completely normal. Source: my SS's RPD shows battery voltage with the engine off, always shows 14+V running.

A battery that only holds 12.0V is done. Just put a new battery in it. It may well solve the problem, but even if it doesn't, it's pointless trying to diagnose electrical problems with an iffy battery.

 

thanks for the comments.

So the second shop ran their diagnostics on it, and they checked the wiring and belts, and came back with a dead alternator. Even they weren't sure how the first shop got 14v on it.

You can start it, but it steadily drops amperage and voltage until it dies. So, until I can get the alternator replaced, I am only running short trips around town, and then put in on a battery charger/conditioner until it's recharged and ready to another trip.

Don't have time to do the repair now, but sometime soon.