1994 Range Rover and the heater won't work it is not the thermostat or the fuses does anyone have any ideas how to fix it?

just maybe somebody by passed the heater core,when standing in front of your engine,look all the way in the back on the left hand side where the fire wall is and look for any weird looking hoses that dont belong there,if the heater core is by passed you should find 2 hoses that are capped off at the ends.