With only an electric fan, the car will start to overheat if driven under say 35 MPH on a hot day. Running the AC will make it worse.

When an engine is run in an overheated condition, heads crack / warp / gaskets fail. Pistons expand and start to wear, oil thins out dramatically causing bearings to wear. Overall it is a bad deal.

The good news is that the engine still has coolant so it will take minutes of stationary time to get temps up and longer than that to damage the engine. Still, overheating is to be avoided.

Have a look on car-part.com , this is a nation wide search of participating salvage yards. Once you find the part call them directly.