1998 Ford Expedition Owner Guide 1st Printing - Page 43

Controls and features Usually, when something affects the compass readings, the compass will correct itself after a few days of operating your vehicle in normal conditions. If the compass still appears to be inaccurate, a manual calibration may be necessary. Refer to Compass calibration adjustment. Most geographic areas (zones) have a magnetic north compass point that varies slightly from the northerly direction on maps. This variation is four degrees between adjacent zones and will become noticeable as the vehicle crosses multiple zones. A correct zone setting will eliminate this error. Refer to Compass zone adjustment. Compass zone adjustment 1. Determine which magnetic zone you are in for your geographic location by referring to the zone map. 1 2 3 13 4 12 5 6 7 8 9 10 11 15 14 43