Weak Rear Window Defroster

I have a 2001 Chevy Impala and noticed that the rear window defroster appears to be very weak. It works, but takes a long time to see the desired effect. Does anyone else have the same issue?

Thanks.

I noticed it as well. You may want to check the wire connections on either side of the inner rear windshield. They protrude out. They may have a loose connect. If you had your windows tinted the Tint Shop disconnects them, sometimes they forget to reconnect them which happend to me in a different car I owned.