well, I learned how to fix a flaky GPS on the F150 this morning. The problem is with larger than stock tires, the speedometer is off, and in areas of weak GPS signal, the nav system depends on the speedometer to keep track of location. When the speedo is inaccurate, the GPS gets confused. According to Ford, you disconnect the battery for at least 20 minutes, then reconnect & drive it. It recallibrates itself.
That's the Ford. The 1992 Dodge just needs a bunch of parts, some of which I bought today. Tomorrow the Jeep gets an oil change.
Tomorrow the Jeep gets an oil change.