Xerox workcentre 3325: photocopies have a 2 inch blurred streak running from top to bottom vertically. I wiped the glass clean and then one copy printed a 2 inch solid black bar in the same exact spot, from top to bottom. It matters not whether I use the document feeder, or the flatbed. How do I fix this issue?

https://www.office.xerox.com/en-lb/multifunction-printers/workcentre-3315-3325/supplies

NO NO NO.

Don't rush things. If you don't know how a laser printer functions, please don't touch anything. Let someone with knowledge clean the machine. Rubbing the wrong roller, can damage the printer bend repair.

Only clean the parts you are allowed to clean. Like removing dust on places outside the printing area.

clean the adf glass

Set the ADF.

First the to do is a "stop test." You will induce a jam before the paper reaches the fuser (which the the hot thing near the exit). The PN for the fuser is 002N02557.

If the defect exists already then the drum or transfer roller or laser may be causing it.
There are very few things that you could clean except the glass on top or the pick rollers.

Whit
Item, Inc.

the problem is in the scanner, open it up and see if you can find any smudges, and clean any obstruction, any ink, liquid eraser residuals, can cause this part to appear as lines on your copied faxed image.
dont concentrate on the printer this is a scanner problem

yes directly

What you need to do is look in the area where your copied pages come out, Between the paper tray and the bottom of the scanner.
On the underside of the scanner you will see a green latch, It is the only green item on the underside of the scanner. About 2 inches long and a half inch wide.
Turn off the machine, push that lever in, then, and it may resist some, pull it toward yourself until it snaps fully to the front of the machine.
Normally what happens is people hit it with the top of their hand removine their copies.
You can take a piece of electrical tape or duct tape and put over it to secure it in place.
You can also, remove the seal glass, the piece of glass about 1 inch wide on the left side of the scanner. It just has 2 phillips screws in it. This with the machine unplugged, and pop that green latch out and flip it around. There is a tab that will keep it from moving. That latch is for shipping purposes.

Clean the glasses on top!!! Your CORONA lens is dirty!!! it must have some cleaning brush or bar near the side!!!

your machine most likely has toner spills in it.
if you send faxes face side down follow these instructions ;
1- take out toner
2- look for thin glass strip on bottom inside the machine
3-wipe clean

if you make copies side up then do the same except look for glass strip on the upper side of machine