It is located on the blower motor housing and is white in color. You have to take the blower motor assembly out as far as I know to get to it.
The blower motor on a 1992 is located under the hood. It is on the firewall on the passenger side.
under the blower motor housing. to the right
under the hood back center of firewall hard to get to
The blower resistor is located behind the dashboard. It is found behind the heater near the center of the vehicle.
Looking at the picture in my Haynes repair manual it looks like the blower motor resistor is in the engine compartment mounted just to the right of your blower motor when looking from the front of the Explorer - Helpfull
Take out your glove box and a few trim and it will be in front of you
If you look in the engine compartment , on the passenger side , towards the firewall you will see the blower motor
Component Location View. RH Lower Instrument Panel
It is located on the right fender near the cowl panel.There should be 3 or 4 relays on the bracket. the one closest to the front of the car should be for the blower.
Probably the blower motor resistor is shot.
open the hood and it's on passenger side under hood