1998 Cadillac Eldorado Owner's Manual - Page 116

Compass Operation Press the COMPASS switch once to turn the compass on or off. When the ignition and the compass feature are on, the compass will show two character boxes for approximately two seconds. After two seconds, the mirror will display the compass heading. If, aftertwo seconds, the displaydoes not show a compass heading ("N' for North, for example), there may be a strong magnetic field interfering with the compass. Such interference may be caused by a magnetic antenna mount, magnetic note pad holder or a similar magnetic item. To adjust forcompass variance: 1. Use the COMPASS button located at the bottom of the mirror. 2. Press and hold the COMPASS button until a zone number appears in the display. 3. Find your current location and variance zone number on the following zone map. Compass Variance The mirror isset .in zone eightupon leaving the factory. It will be necessary to adjust the compass to compensate for compassvariance if you live outside zone eight. Under certain circumstances, as during along distance cross-country trip, it willbe necessary to adjustfor compass variance. Compass variance is the difference between earth's magnetic north and true geographic north. If not adjusted to account for compass variance, your compass could give false readings. 2-46