Cooling fan question
 

I have a 1998 C230. This morning i was going to go to work and found that the cooling fan was working in full. I start the car (outside temp was under 60 degrees) and everything was ok. I took it for a few blocks drive and came back home. The fan did not work right away, but few minutes later, it started again and did not stop for 15 minutes... 'till i took out the fuse. As soon as i put the fues back...the fan starts working.
what can it be??? a fan failure??? a ghost???
Please, i need advise