Main cooling fan does not work. Why?

I have a 1988 T-Bird Turbo Coupe.

The main cooling fan does not run at all. The secondary, A/C fan, does run.

I applied power to the main fan an it runs, so the problem seems to be eleictrical ... either a fuse or broken wire.

I've looked at the electrical diagrams but can't figure this out.

I also cannot locate the temperature switch on the engine block. Can someone point me in a direction?

Any help/ideas are greatly appreciated.

~Rick

Check for a relay or temperature sending unit malfunction also