The overall code coverage is not being cleared, I have a trigger with no lines of code in it and it still shows as if it had 24 and only 58% of it covered.

How can I force salesforce to retest that trigger so it no longer shows like that since I think is affecting a new class I need to deploy, the new class has a code coverage of 82% but when I try to deploy it I get an error that my code coverage is 71%