Only one radiator fan turning on

I recently bought a 2012 Scion Tc. The other day the red
coolant light was blinking. I noticed the ac having a
problem with cold air. I was stuck in traffic in 100+
weather. I turned the ac off and drove home with no more
over heating light. I got Home popped the hood and
checked. I saw only one radiator fan running. Turn the air
back on, checked the fans again and only the one fan was
still running.

This is is what I have done.
I’ve replaced the relay for the fans so I know they are
good
ive ran direct power from the battery to the fan that wasn’t
coming on. It turns on perfectly.
ive switched the plugs for the 2 fans and drove it to see
what would happen. Only one fan came on still. It’s the
other fan though because I switched the plugs for them
I’ve replaced the coolant temperature sensor
I also used a multi meter and tested the relays, and for
continuity in the cables to the fan and it’s all good.
I can really use some help.

thank you