wait..... What did it do before he messed with it... because you said this was after he put a belt on?
My n14 When I start the fan still moves alittle.. free spins tho. I didn't trust my ECM to throw fan on so I ran a man. switch (didn't have one) to the fan so I knew if it worked if I needed it to. I was like you I didn't want it to overheat.....
ALSO... when the motor is running you can take the air hose off of the air solenoid that controls the air to the fan clutch to see if it works..... If you take that line off it cuts the air to that fan clutch the fan should kick on....That clutch has constant air going to it for the fan to be off... When 0 air is getting to the fan clutch it should run..