2001 Mercury Cougar 31 fuse keeps popping
 

The engine is a V6..The #31fuse keeps popping...The alternator was changed last summer and Could it not be the alternator? What can be causing this fuse to pop? Thank you

There is either a short to ground or whatever device is receiving its power through fuse 31 is drawing too much current.

The dashboard lights go out and the alternator is not getting charged. The alternator was changed in the summer. Would it be expensive to fix by a mechanic that does this type of work?

The alternator keeps the battery charged, it does not "get charged". Looking in your user's manual, what circuit does fuse 31 protect? You can also look on the back of the panel which covers up the fuse panel.
Electrical problems often are the easiest to "fix" but can be the most difficult to troubleshoot. So it is difficult to answer your question relating to cost.

Fuse 31 protects panel dimmer, license plate illumination, glove box lamp and belt minder module. I would start where the environment is harshest, at the license plate.
 
 




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