tonight while driving home my head lights kept dimming as i drove down the road. anyone had this problem? is it an electrical problem?

First thing that comes to my mind All Things is the inadequate ground lug that goes from the negative post of the body GM bolted to the painted surface of the floor pan under the back seat. Being yours is an 04, it might be all oxidized. Some 04'* have had this bolt rust thru.

STRUCTURE:BODY Bulletin Number: 050861002
Bulletin Date: MAR 2005
Vehicle. Pontiac Bonneville
Summary:
FLOOR PAN CORROSION PERFORATION IN BATTERY COMPARTMENT. NHTSA ITEM NUMBER - 10013452 )

I realized the ground was inadequate when I put in an Alpine Subwoofer amp in and the lights dimmed with the music. It was kind of cool/ but not cool, if ya know what I mean. I removed the bolt, replaced the ground lug with a larger copper one. Then sanded off the paint where the ground lug bolted on and covered it with No-Ox grease. No more dancing headlights. Not sure if this is what is causing your problem, but it'* a good starting point.

thanx for replying so fast venom. is this something ai should do on my own or should i take it to the dealership?

It'* really as simple as I stated and you can do it. You can buy a slightly larger lug ( copper) and a small tube of No-Ox grease at Lowes in the electrical dept. Even if You leave the OEM lug, just sanding the paint off and reattaching will give you a much better connection. I needed all I could get for my amp, air compressors, light kits, selenoid valves and switches for air bags/struts, and the ones for the nitrous kit and purges,....so I changed the lug as well. I keep thinking my OEM alternator is going to smoke, but I'm going to get all the goodness I can out of it before I replace it. Besides,.... You Know I'm gonna try to get Mr GoodWretch to replace it first.

cool I'll probably do it I just hope thats the reason. my warranty runs out soon and I wanna have it nipped in the bud before it does. this is the first time Ive noticed it so I'll check it out tomorrow.

Ya, I would do that yourself and see if it clears. Run the A/C with the lights on just to make sure of no flickering. Then if that doesnt do it, then I would take it to GM. Did You have your foglights on at the same time? And if so, have you had the fog lamp harness replaced?

Also your lights will dim when your Alternator shuts off... It will do this when your battery has reached a full charge. I have noticed every once and a while my lights and sometimes heater will cut out for a split second. this is normal even my mothers new van does it aswell as both my sisters escalades .

But do check into that ground and follow venoms instructions

No I wasn't running the fog lights because get this one of them is out again lol and this is after I had the harness replaced. The service tech told me the reason my fog light keeps going out is because the housing is loose and so the bulb is not burning out but the housing is what grounds the fog lights and thus when it comes loose I have one fog light out (always the driver side). So I have to take it back to the dealership so the can replace my fog light housing. if any of that mad sense lol I kinda talk in circles

I'm pretty sure the dealers know about the bolt problem. There must be a bulletin out on it or something. Definitely take it in.

My 2005 has been doing it since I got the car new. My battery apparently went bad and the dealer replaced the battery and the bolt under warranty at 15,000 miles(?).
It still dims once in awhile. I can't really say if it'* better, or I'm getting used to it. It'* not just at night, it happens day/night - driving/idleing. It only lasts for about a second, but if you're quick, you can see the voltage drop.

I'm at 32,000 miles now.

Yea thats exactly what happened. But I only noticed at night, I don't think my voltage drop but I'm sure as I wasn't paying attention to it I was focused on my lights and they dimmed for a second and then they were fine and then they dimmed for a second and then they were fine again and then I didn't notice it again for the rest of the ride home.