How to hot wire cooling fan

The bigger question is--why do you want to hot wire it?

If it isn't working, the better option is fo figure out why. Hot wiring it can only lead to further issues down the road, or immediate ones if you mess it up.

The fans may also run when the car is not running and a hot wire isn't going to provide that mode. That will be another issue to create problems.

Those fans are turned on by the ECU when a sensor tells the ECU the temp has reached the trigger point and above.

So, start with the fuses, then the sensor, then whatever the ECU uses to turn it on - relay, MOSFET etc., then the ECU.

Fix it, don't jerry rig it - that is only for sailors.