One problem related to steering rod relay connection has been reported for the 1998 Mercury Grand Marquis. The most recently reported issues are listed below.
My 1998 Mercury Grand Marquis at slow speed had the passenger side tie rod end fail and fall off causing complete loss of steering. This happened at a slow speed luckily no accident. Car towed to Ford dealer. Replaced all four tie rod ends. Cost $400. 00. Car had 50,000 miles , this was a factory defect. This is a sealed unit requiring no grease or maintenance. I replaced with greased tie rodends. I believe this should be a recalled part.