I have an '88 Mercury Sable. Pulling codes on it requires an analog multimeter, and a paper clip. I don't have the book in front of me, but I recall there is a connector in the engine bay on the passenger side firewall. Pull the cap off it, put the negative lead from the meter somewhere in there and connect the positive lead to + on battery. Then paper clip two other connections and count the meter needle sweeps. I also have a chart of the codes and what they mean. I assume they also work with '85.