Right around my relays I notice some kind of blue crimp and the ends of a wire
http://imageshack.us/photo/my-images/706/img0215om.jpg/

And apparently it leads to this wire
http://imageshack.us/photo/my-images/52/img0216hg.jpg/

which if I ground, leads to the left radiator fan starting at the first click of the key.

Is this normal? or a mod by the PO?

and by the way, what is that red cylinder in the second pic?

 

I could be wrong but the red can could be an aftermarket horn maybe? Thats my best guess.

 

definitely not stock, someone modified the setup. as-is, it looks like they bypassed the factory switch in the head to have the fan running all the time the vehicle's running. as for the red part, i agree that it looks like a horn from the photo

 

Be glad the PO actually knew how to control a relay and didnt just chop it all up like most shade tree "fixes" consist of. Leave the ground off and replace the thermal switch. If you want total control over the circuit, move it from ground to a toggle switch in the interior so you can turn it on/off. The fan motor is not meant to run continuous

 

Is there a likely chance of that fan breaking if I leave it continuous? Idk what the manufacturer's intentions were for the fan.

When is it supposed to turn on originally?

 

i had done something similar on my last engine swap (sbc 400) without issue. it will mean you have a shorter life span on the fan motor and possibly take longer to get the car up to temp, but its not "harmful". the fans were originally designed to only come on when the switch in the head got to a specific temperature.

 

The fan motor will burn up quickly which will leave you cooking in traffic when you least expect it

As the motor expires, the current required to turn it goes up so the fusible links can blow and wires melt. Those are fun to replace