GDATL

The title is the short and sweet problem, but here is how I got there:

Driving my 2007 Impala LT3 3.9L on I-85 in Atlanta, the battery light came on. Within a few miles, the A/C quit cooling (Battery Saver? but warning did not show). A few miles further and in front of my Chevy dealer, the dash board lit up like a Christmas tree (all lights on) and so I turned in and pulled into the service center – this was right at closing time on July 3rd.

Before the service writer came out, I looked under the hood and noticed a LOT of corrosion at the battery posts. The battery was a Bosch replacement battery, 3-4 years old. Service writer (good guy, this dealer services my car regularly) said I definitely needed a new battery because that one was leaking a bit around the posts. The car would not start when they tried to move it into a service bay.

They replaced the battery (discounted price and charged nothing to install it). I was the last customer to leave and they locked the doors behind me. About 2 miles down the road, the battery light came on again, followed by the "Service Charging System" warning. My first thought was "alternator." Dealer didn't answer phone, and so I proceeded home.

On July 6th, I drove the Impala about a mile or two with no problems, no indicator lights and no warnings. So now, I was thinking - maybe this was just a re-calibration of some sort. On July 7th, the battery light came on after driving about 2 miles, followed by the "Battery Saver Active" warning and the A/C cut off. I drove home, charged the battery fully, and on July 8th drove 5 miles to the dealer for service, with the battery light on, the "Battery Saver Active" warning shown and all lights, radio and A/C turned off.

Chevy dealers are so busy this time of year and this is compounded by the GM recalls, so I understood when they told me it would be a couple of days before they could look at it. On Friday, July 11th I learned the car needed an alternator and it was $600+ for the Delco (Bosch) alternator and $200+ for installation. They did not have a rebuilt generator. I declined the service and paid $49 for the diagnostics.

I purchased a rebuilt Bosch alternator from AutoZone for $171 and paid $85 to have my car towed back home. I figured that for $250 and a couple of hours of work, I would save $550! I installed the alternator with no problems. I disconnected the battery completely before started the work, and charged the battery while I was replacing the alternator. My charger showed a full charge on the battery.

I tried to start the car, and the first time I turned the key, it turned over (barely, for a fraction of a second) and then stopped. It still won’t start.

Sometimes when I turn the key to the “on” position, the dash looks normal. When I turn the key to “start” sometimes the dash lights (and all other electrical components) die completely and then a few seconds later, the lights will come back on. Other times, I hear a few clicks (starter, electrical relay ??) and the dash lights flash on and off. There may be a pattern to it, but I am at a total loss.

2 other points: 1) Checked with my OBDC scanner, no codes. 2) Using a cigarette lighter voltage reader, the battery reads 12.6V. After trying to start it and watching the dash go dead, the reading drops to 6V or so for a minute before the dash seems to "reset" and starts reading 12.6V again.

I have checked all fuses and they look OK. I have not checked the starter relay (I’m told that it is same specs as the rear window defroster so I would switch them.) I will do that next. Then I am going to try the GM Theft Deterrent “ReLearn” Procedure for the Passkey III. I will do that with a charger attached to the battery.

Once I try those, I have reached the limits of my knowledge and would appreciate any advice.

therewolf

Hi GDATL, Welcome to the Chevy Forums.

Sounds like a very simple, low cost problem to me.

Replace the battery cables. (NOT just the posts)

Replace the engine to firewall ground-strap.

At the very least, this low cost job(DIY) will

level the playing field.

But it sounds like cables to me.

GDATL

Thanks, I can try that, but it will be tomorrow night before I can do it. Certainly better than leaving the car for another 3 days at the dealer!

Because the battery previously had low voltage and/or because I left the battery completely disconnected (and charging) while I replaced the alternator -- about an hour of work, but it took me about 2 hours -- would there be a need to do the PassKey Relearn process??

Also wonder if the low voltage (ran several miles with "battery saver active" warning) could have caused the BCM to lose programming (if so, guess that is a dealer trip!).

Any other things you would suggest to check?

GDATL

Before going through the expense of replacing the battery cables as suggested above (a good idea, but my son recommended this alternative) I decided to try jump starting the car just to see if that made a difference. I didn't expect that it would, since the battery showed 12.6V, had been fully charged using an external charger (while out of the car), but I tried it anyway.

The car started! I let the car run to charge the battery for a couple of hours (my little cig lighter monitor was reading about 14V) and after I turned it off, it would NOT restart. I would think that points to a high probability of 2 problems:

1) The new battery is BAD.
2) The positive battery cable is bad (since I used the positive connection at the top of the power distribution center)

I will DRIVE the car back to the dealer tomorrow and tell THEM to check the battery, and if the battery is good, ask them to tell me what they think.



Thanks!

sledge.impy

Get a real voltmeter. They're not expensive at Sears.

Is there corrosion at the starter where it hooks up?

I've only had to splice a new wire on a 92 lumina 3.1L ages ago.

If there is no corrosion on your battery terminal cables they shouldn't be bad.. Work some Coca-cola on them if you do have it. the phosphorous will eat it away.. Or get some battery terminal cleaner & lube at the autoparts store.

YOu don't mention how it won't start. Is it cranking? Or just totally dead? Lights on panel? headlights work ? do the headlights dim when trying to start?

Kind of odd to have a CCA problem in the middle of summer...

GDATL

Thanks for the input! If I don't find my multimeter today, I will definitely be buying one! With my "toy gauge" the only thing I can measure is the voltage coming out at the cigarette lighter!

The problem has "evolved" as strange as it sounds!

On Saturday, when I first put in the new alternator you would turn the key on and dash would light up normally, hit start, and you would hear a click from the front (probably starter solenoid) and a whir from the back (probably fuel pump) then all the dash lights would flash on and off about once per second for 10-15 seconds. Then everything would go off for about 10-15 seconds, then the odometer only would come back on.

Now, after jumping the car and letting it run for 2 hours to charge (I know, wasting gas, charger is better) it acts differently! Now,you turn the key on and dash will light up normally, hit start, and you hear a click from the front (probably starter solenoid) and a whir from the back (probably fuel pump) then the dash and all lights (interior, too) would go dead and stay dead for about 10 -15 seconds, then the odometer only appears and interior lights come back on.

When I jump the car, it starts a little slowly (yes, somewhat like a cold weather CCA problem). but nothing else abnormal.

Yesterday, when I jumped the car, I used the jump connector on the Power Distribution Block (the under-hood fuse box). After running 2 hours, it wouldn't start when I turned it on. Today, the battery reads 12.7 volts but I jumped it from my wife's car, but this time, just to see if it made a difference, I connected directly to the battery post. Still started, no difference - so if it is the battery cable, it is probably NOT the segment going to the Power Distribution Block, it is probably the section that goes to the starter -- just a guess.

shundertmark

I have a 2007 Chevy Impala as well and am having almost the exact same issue. Just curious what it ended up being, as I didn't see that in the thread. I'm baffled as well.... Thanks