Can you use the blower motor wire to run an electric fan?

I still have the orange wire that once supplied power to the heater blower motor on my Chevelle in the engine compartment.

Since the heater box is long gone I was thinking of using this wire to run power to my electric fan. That way it'll spare me of having to run extra wires while having unused wires just sitting in the engine compartment.

I also removed the fan switch on the dash but the electrical connections are still there....IIRC I think it's a gray wire off the 30 amp fuse to the switch then onto the big orange wire.....I was thinking of hard-wiring both together so the fan would run directly off of the fused power from the fuse box.

I believe my fan only draws like 18 amps max and the fuse holder for the blower motor is rated at 30....to me it doesn't sound like there'd be a problem but I wanted to ask first before I did it.

Thanx.