Flickering lights

[chris_gt_74]

I need some help here. I just noticed last night when I started up my car that all the lights on my car were flickering. Not on and off but like fluttering. I affected the headlights, tail lights, and all interior lights. I can't get it to do it every time though. My battery is less than a few months old and has been checked for tightness and corrosion and my alternator has also been tested today showing 14v + all three times it was tested. The only abnormal thing I have noticed recently is my key will sometimes act like it doesn't want to turn so I pull it out and flip the key around and it turns just fine. I am kind of at a loss as to where to look for this issue and honestly I don't know how long it's been doing it. Any suggestions would be greatly appreciated.

Oh and to add, the car runs fine with no apparent power change. Also the radio does not cut out so I am not losing power. Oh and I also noticed that it's worse when the a/c blower was on high. Turning it off made it flicker less or not at all. Could it be a grounding issue or bcm? Likely unrelated but just in case, it was recently tuned with some help from a guy on the forum.

[Superdave]

alternator is probably going bad, but check all the major grounds first.

[robert 1980]

Yeah mine did the same thing.Then i changed my alternator and it was fine=) It's scary as hell when it does it on the highway.lol

[chris_gt_74]

Well I went and picked one up today and changed it. The problem appears to be gone. Thanks

[robert 1980]

Cool good to hear that=)

[chris_gt_74]

Me too lol. Of course the next project is a noisy timing chain.

[robert 1980]

Im really happy with my double roller chain.But i hear GM is the next best thing.Stay away from the cloynes timing set.

[chris_gt_74]

Yeah Im gonna go with the gm one and may go ahead and change the gears and damper too.

But it does appear though I spoke to soon on the light flickering. Even after the new alternator it is still flickering. I only seems to happen though when I want to use my ac. It's a pulsing kind of. The lights don't actually turn on and off but it is noticeable with all of the cars lights when it happens. I doubt it may help any but I am going to flash my pcm back to stock just so I can rule out any possibilty of it being from the recent tune.

[chris_gt_74]

Well I flashed back to the stock tune and so far I am using the ac and I have no flickering. Time will tell if something in there was causing it.

[robert 1980]

Well I flashed back to the stock tune and so far I am using the ac and I have no flickering. Time will tell if something in there was causing it.

Who tuned the car for you? What year, make is this car anyways?Just curious.

[chris_gt_74]

Gectek is who was helping me out with it. I have an 05 Grand AM GT 3.4l. If it is indeed due to something in the tune it was likely due to something in the supposedly stock bin file we both found for my year vehicle. We flashed the bin first after he made some changes in tiny tuner I'm guessing and then downloaded the hpt file. He made some adjustments and we reflashed the hpt file. The car ran great but with the exception of the light problem which I didn't notice right away, if it was even there. I honestly don't know if the bin file had some effect or not but since flashing back last night I have driven about half a dozen times and used the ac with no flickering as of yet.