i have got an 89 rs and i was working on it... i had just replaced the BAT wire and was letting it run to make sure that i installed it correctly. turned it off and checked the fuses then truned it back on and it was making a horrible clicking noise. turned it of.... couldnt figure out what it was, so i decided to turn it back on again, this time, metal or plastic or both started flying from the front of the motor (i didnt stick around to long to make sure) turned it off and i havent turned it back on since. if anyone can think of anything other than the fan that could be the prob please let me know thanks guys.

 

Unplug the harness from the fan motor and try it again. One weatherpak connector on the bottom side of the fan motor.

 

With flying chunks of plastic you should be able to figure out easily what came apart on you. Chances are the fan or it's shroud were colliding for some reason, maybe even touching the backside of the radiator. Regardless, the mechanical interference needs to be fixed first, then figure out if the motor that drives it is shot.

A replacement unit is as close as your local junkyard. Easier to grab everything in one shot from a donor car- fan, shroud, motor, brackets that attach everything, etc. than doing it one piece at a time with new parts from GM or the local parts store.