Lincoln/Mercury Repair: 2001 Lincoln Executive Town Car compass, executive town car, compass module

Question
My compass works OK part of the time and then it will start wandering.  The display will go blank for a while and then come back on and wander between all the directions. It may do this for a while and then later start working again. I never know when it will work and when it won't. The problem seems to be totally random. I set the zone for 9 (East Tennessee) and have driven in a circle until the "circle slowly" indication goes out. I have repeated this several times but the random problem always comes back. I have trouble getting it to go into the calibration mode (this one requires the button on top of the mirror to be pushed and held for several seconds with the motor running, the doors closed and the A/C and radio turned off). Sometimes it will go into the calibration mode and sometimes it won't. The compass module is at the base of the rear view mirror. I sprayed the connections with a good electronic cleaner where the cable plugs into the module. Do you have any suggestions?  

Answer
Yes, replace the modual on the rear view mirror. The are wicked sensitive and cleaning the front windshield people have a tendency to knock them off the mirror stem. Pressing them back on will wack the printed circuit board inside. I have replaced two in mine due to careless carwashers.