'93 Grand Am 3.3l; Need help accessing trouble codes

My Haynes manual is pathetic when it comes to explaining how to access trouble codes. It does mention jumpering the A-B terminals on the diagnostic connector below the steering wheel, but what do I do then? Start engine?, turn key to run?, Do lights blink, or do I watch a dash indicator??? Maybe it's relayed by Divine intervention? Help!

after jumping the two leads/pins together (paperclip or GM code key), turn ignition to on/run, DO NOT CRANK, and watch the engine light (service engine soon).
it should flash an eleven or twelve (I think)
in other words, the light will blink(FLASH) once, then PAUSE, then FLASH,FLASH again (I think it is a code 12: 1-2 for the start of the codes on your specific vehicle)
then it will PAUSE again before starting with the next, always going low to high numbers (ex:12, 51, 75, 155, etc) possibly a code twenty-three:
FLASH, FLASH, PAUSE, FLASH, FLASH, FLASH, pause...
once it is complete it will FLASH you the code number from the start (a twelve I am pretty sure) and then repeat itself, if you missed any, or you can turn off the ignition key.
with codes in hand, consult your book, a website on OBD I codes, or post them and myself or others can possibly assist.

hope this helps,
ctesla

Thanks, ctesla, that is EXACTLY the info. I was looking for. Don't know why it wasn't in Haynes.