I can't find the connector to plug my scan tool in. That F250 1989 4x4 has a check engine light on.
Didn't see anything under the dash.. should have a odbc 1 connector somewhere. I did find what looks to be like the computer.
Any one how where the OBD1 port is on 1989 F250 4X4.?

 

Should be on the driver's side, right behind the air box.

 

I know this is pretty late, but I happened on to a very valuable website that any Ford owner should read.
It is www.fordfuelinjection.com.
I learned an incredible amound about my truck.
This should help you with your problem as well.
Rick