One problem related to turn signal has been reported for the 2002 Mercury Grand Marquis. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Mercury Grand Marquis based on all problems reported for the 2002 Grand Marquis.
Problems with my wife's 2002 Mercury Grand Marquis LS not cranking at odd times. I have cranked up the car, and driven it into the garage, then go back out a couple minute later - 15-30 minutes - and the car would not crank. The last time I pulled the car into the garage one evening and when my wife went to go to work the next morning it would not crank. The dealer's service department can not find a problem. However, the left turn signal went out about a year ago, requiring a module be replaced. After that we noticed the foot pedal adjustment diid not work and a loose connection was found to be the problem. The starting problems did not start until after the turn signal module was replaced. I have found other incidents of problems with the ignition switch for this model Mercury.