just bought an 87 iroc z28, wondering why old owner has a wire running from the harness on the back of the fan to a 50 amp fuse then throught the fire wall. not sure where its running from there. the car over heats unless i am going at a constant speed. i figured water pump or clogged up thermostat. but maybe it has something to do with this wire for the fan. p.s. the fan does not work. anyhelp would be great. i am still trouble shooting this myself. ill update if i find anything else.

 

probably wired the fun to a switch 12v or similar because it stoped working as its supposed to. follow the wire throught the firewall and see where it goes. test the fan itself and make sure its not burnt out.

youre over heating because you have no working fan....if you havent figured that one out yet.