Ticking noise in front of engine

I have a 2002 Treailblazer. I get an interminet ticking noise in fromn to engine. Seesm to be when the fan clutch is nbot egaged but have check the clutch and it not it. The sound appears to come from behind the pulley on the engine.
Have not taken back to dealer but a friend who is a mechanic doenst know and has aked a dealer and they have not encountered.

Ideas?

Pretty sure it is the fan clutch that needs replacing. Mine did that & after they replaced it, it went away.
Sad to say, something again is making the ticking noise under the hood & it is going back Wednesday.
Will reply with what they find.