The Dreaded Check Engine Light

It happened a while ago.  Ok...it happened a couple years ago.  The "check engine" light came on in my car.  Then, just as quickly as it came on, it went off.  Since then, it's come on and gone off hundreds of times and my car has been running just fine.  I thought I had it figured out - "ignore it...and nothing is wrong."

Yesterday it came on again.  But this time it's different.  My blower - that keeps me warm in the winter and cool in the summer - is also now acting up.  It's only running at the highest level (5) and I get nothing at the other 4 levels.  Perhaps it's time to take the "check engine" light seriously.  Then again...it is warming up and I do love driving with the windows down.  Hmmmm.