I have a intermitting battery charging system light that comes on whenever!it stays on when in park.we changed the alternator made sure no wires are pinched and checked the battery terminals! My dash lights flicker when its on..help!!

 

Did you check the battery cables at both ends for corrosion or loose connections? Also check the belt that drives the alternator. If it is loose and slipping it will cause that problem.

 

we did not check the belt!

 

Check for any loose grounds ans this will cause all kinds of gremlins to appear. Have you had any work done recently? My parents chevy was having similar problems soon after their start was placed by a local shop. I found that they did not fully tighten the 12V connections on the starter.

 

What year Impala?

How old is the battery?