Toyota Camry: 96 Chevy Impala SS

Son has a 96 Impala (68k miles) and the primary cooling fan stopped working. (Secondary fan was replaced recently and works fine.) Replaced it and still doesn't work. Tested new and old fan by hotwiring directly to battery and both work.
Checked relays, fuses, and replaced the sensor on the front of the water pump.
Question: Does this vehicle have a cooling switch, and if so, where exactly is it? Could this be the cause of the problem? If not, what else could it be?

No messages from the computer. Everything appears normal-only the Primary fan never comes on. Only secondary one.

When did Toyota make a Chevy Impala? Getting a bit over zealous with
the post to "all" newsgroups, huh?