At what instance did this momentary voltage dip occur? Did it happen for no apparent reason?

happened right when i hit the button to roll two windows up at the same time.

so if i were to address this issue, first step would be to get the alternator checked at autozone. if it fails, replace it. check battery cables too, just to cover bases.

and if it passes, new plugs and wires?

or is there another issue that the strain on the alternator is just revealing to me that i need to address?

Right, *possibly* another issue that the weaker voltage is revealing. There'* plenty of chance that nothing is wrong as far as spark to the cylinders. That'* why I stated it wouldn't hurt to at least just check it after you get the voltage issue resolved.

UPDATE: been awhile, but thought id post the resolution.

swapped the plugs/wires. the problem is gone.

Interesting. I wonder if the old wires/plugs had enough resistance that they were drawing the current down enough to not quite misfire..but cause a lesser than acceptable spark.

That'* interesting, because I once posted a similar observation from my '92 SSE */c and '93 SSEi , and the alternators, plugs, and wires are fine. I observed that the boost gage reading becomes a little more positive when idling and a window is rolled down or up (or when pushing the up switch when the window is already up).
Does your boost gage move when you roll the windows up or down? Mine does, and it happens consistently on both of my bonnies, but it'* only noticeable while idling.

Just for grins, I think you ought to do a careful inspection of your battery cables. Every car that I've owned that ever had the headlights dim when you do other electrical things had corroded battery cables.

I don't just mean the connector at the battery, either. I mean corrosion down the length of the cable, typically the positive cable, inside the insulating sheath. This eventually manifested itself by the car refusing to start after driving places. After shotgunning replacing the battery and alternator, the battery cables were the missing link. Just check them, okay?

Also, some other members had corrosion at the grounding point of many wires in an area under the carpet on the passenger side interior. While I have not experienced that, it'* another culprit of bizarre electrical issues.