My 06 Grand Prix GT...

A while back I replaced my starter with a new one because I thought it was going bad, turns out it was the theft deterrent module around the key.
I have 2 AGM Batts, one on an isolator so my cars stereo never kills the main battery when off...
I did the big 3 upgrade with 1/0 AWG a good while back..
Also replaced the ignition switch with a new Delco one..

Some mornings it will click rapidly once I turn the key, but not start.
Occasionally it will try to turnover, then after a few tries it will do nothing, then eventually the DIC shows charging system failure error, traction control, etc..
If I hook a charger to the batt it will show as 0% charged, if I disconnect the cables to the car, the battery then will show as 100% charged on the charger...
Disconnecting and reconnecting the posts usually allows it to start..
It may be the starter, as sometimes it also hesitates to turn over, then as I let off the key it tries again on its own, and starts...

Any ideas?
I could put the old starter back on, as it was never the issue, but I'd rather out another new one, as it is a small pain to swap, easy though...

Once I replace the theft module on the ignition switch the remote start stopped working...
I have a fairly new 450$ power bastards Alternator, puts out 125A at idle, and 250A at 1,200 and up RPM...
It is deff charging the batts.

We need to be sure the battery is up to snuff when attempting to start and see what it does?
From what you state I'm not convinced we have a good battery or not. Seems the charging system is working. At least the alternator is putting out.

It is weird, when it is colder, or if the car sits overnight then that is when it has the issue mainly..
If I disconnect the batt cable negative, wait a minute, then reconnect, it will allow me to start it usually, if not the first crank, then after a few attempts.
Some attempts you do not hear the starter try to engage at all, just a bunch of fast clicks from what sounds like a relay near the dash area, not the glovebox... Once I hear those it will not try to start at all again till I disconnect the battery, and reconnect it..

It should not be reading from the batt I have in the rear as it is on an isolator, it does click on once the key is turned once, so that may be why I see the battery voltage variants on the charger.
I'll try to remember to leave the hood up a tad, and open it before I "wake" the car up, and see what my voltmeter says.
And I'll disconnect the ground to the main batt, and see what the voltmeter says for it...
I know isolators don't work as well as they should on newer vehicles due to the kind of alternators, variable voltage, etc.. But I don't think mine is considered a "smart alternator", it was 450.00 though, lol

Probably does not matter, but the starter I put in a few months back was a new REMY 96208 / Remy Gold..
The remote start quit working when I installed that and the theft deterrent module..
Shortly after I started having ignitions issues again, which I thought I had fixed with the TD module and new starter, pretty sure it was the TD module all along at first....

What carfixer007 said ^^^^^^^

. . . and:

Is this based off of a voltmeter or is this just the ratings?

What is the voltage at the starter battery when the car is idling?

I have not checked the output myself, but I trusted the company.
This is my alt.
https://www.powerbastards.com/prodde...1127-250-HD1-5

When idling the DIC shows 14-14.4v

Sometimes I turn the ignition and it will not even engage the starter, as it does not try to engage.
I'll try to check it this morning, it is chilly and dark, by the time I have to go I may not have time to check the battery again, but I will check it ASAP and post what I find, thanks guys!

Left the charger on it all night, it was cold this morning, it cranked up right away, so I am leaning towards my main battery either failing, or a parasitic drain dropping the voltage so low it can barely start of at all..
If it is the battery I am getting the same AGM I have in the back, dropping the isolator, and wiring the batts in parallel with 1/0 AWG, I have the 1/0 Power from the batt, but I do not have a ground, my isolator and rear batt are grounded to the chassis since they were on an isolator, and I was told it did not matter.

I am eyeing this, even though it is not the die hard platinum I have in the trunk, it is better by far IMO, Interstate batts are top notch...


Just hard to know the manufacturer date if you buy online, I have heard bad things about local parts stores having old batteries that have to be charged..

How old is the battery?

As a test, you could swap the batteries and see if the behavior changes.