I have a Honda pilot 2004 the radiator fan works iwhen I on the AC or when the engine gets to a certain tempreture.
But I want the fan to work when I on the ignition so can I pass the fan to work directly . Thanks

 

yes you can, place a hot switch directly to the fan using a fuse for safety and turn on at will with engine running or not running. with ignition off . just be aware if you forget to turn the switch off, your battery will go dead.

 

I know this is old but wanted anyone wanting to do this to know that if you used a “piggy back” plug in fuse adapter on the ignition fuse to a switch that controls a relay coil (and a 1N4003 diode REVERSE BIASED across the coil to prevent back EMF when the relay Coil is de-energized ) and then come off the battery thru a fuse to the fan via that relay’s N/O contacts it would not drain the battery when the ignition is turned off.
The attached photo is for reference only to show the space with blue fuse is for ignition fuse and yellow fuse placement for the relay coil via the switch that will energize the relay that will manually turn fan on and off.

You nees to get correct style holder for your particular car