driver side window only works in the morning

I am stumped! I have VERY little car knowledge, so any advice needs to be very elementary. The driver side window of my 2000 (4door) taurus will only work for about the first 5-10 minutes the car is initially started for the day. The window will go up or down, but it will just stop working, sometime with the window down, sometime once the window is up. It might be my imagination, but when I try the window switch, when the window is no longer working, it seems like I hear a clicking noise. The next morning, the window will work again for 5-10 minutes. PLEASE help me! I need to know what part to buy, where it goes, and how to install it. Thank you in advance for any and help!

Have a wonderful day,

Laura

relay or motor.

relay: look on a wiring diagram and see if the relay operates anything else.

motor: old grease in the motor may have hardened and is causing the motor to bind up. Or the motor is worn out.

Thanks for the help! Does anyone have any advice on where to find a wiring diagram that shows the relay w/out spending lots of$$$$? Also, how would I check the motor to find out if old grease is hardened... why would the window only work in the morning?

Thanks in advance to all who reply.