Here is a picture of the OBD I connector:
Do you need a wiring diagram for the vehicle?
You can view the diagrams at these links:
Did you try this link? This has all the wiring diagrams for 88-98 so you can compare them. Go to bottom of page and click on view diagrams.
Also check these links:
Did you look at the OBD I diagram above? It shows what each pin is for.
If you intend to use a 97 wiring harness and computer and components, you should be using a OBDII C-100 connector.
Is this is what your looking for?
OBD 2 pinout for GM cars
Should be suitable for most modern GM cars - Buick, Cadillac, Chevrolet, DaewooGMC, Holden, Opel, Vauxhall.
Most GM cars produced in 1996-2003 use J1850-VPW interface. GM cars produced in 2003-2006 use J1850-VPW interface or CAN. Most cars produced after 2006 are equipped with CAN bus.
Since 2002, there is another pinout - GM-LAN (for vehicles equipped with CAN bus)
OBD-2 ISO 9141-2 (14230-4, KWP2000) simple serial cableOBD-2 J1850 PWM, J1850 VPW serial ELM327 cableOBD-2 universal ISO 15765-4 CAN, SAE J1850 PWM, SAE J1850 VPW, ISO 9141-2, ISO 14230-4 and SAE J1939 diagnostic cable