One problem related to battery has been reported for the 2005 Mercury Mariner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Mercury Mariner based on all problems reported for the 2005 Mariner.
2005 Mercury Mariner. Vehicle running just fine, except starting sluggish. Needed new battery. I changed it. Right away it began to shift rough on 3 shift (automatic). Read manual and it stated to give time for computer to reset to drive conditions. After 3 weeks I set up appointment with dealership. They charged $119. 00, and stated that they updated the computer, but it still did same thing. They informed me they called Ford, and was told to replace the transmission for $3500. The technician did not seem convinced of that, and said fluid was fine and did not smell burnt. Said to drive longer. I have written to Ford to no avail. They also stated the reason it did not do it with the old battery was due to the computer covering the rough shift. I talked to a transmission expert. He just could not see that being possible.