Hi,
If you are looking for the data link connector (DLC), it is in the vehicle under the dash on the driver's side of the vehicle. It should be visible.
I attached a pic below showing the location. See if you are able to find it. If you can't let me know. Also, here is a link that explains how to retrieve codes from the OBD1 system for a GM vehicle.
https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method
Let me know if this helps or if you have other questions.
Take care,
Joe
See pic below.
Image (Click to make bigger)
Saturday, November 26th, 2022 AT 11:13 PM