I have a 1998 Ford Explorer, the temperature gage works fine, and there is plenty of antifreeze in the reservoir and the radiator. I select the controller for the front heat NO HEAT & NO BLOWER.

There is a door under the dash that switches the air from hot to cold. It is controlled by an electric actuator behind the radio or a vacuum switch under the dash. The doors are bad about breaking inside the heater box under the dash and won't let it switch from hot to cold. Expensive job. Dash has to come out.

If the blower motor fails you will not get any hot air. I threw away my Hayne manuals for that year. Maybe there is a chance the blower is under the hood (maybe) Check the blower motor and switches first.

You're in luck. I did not throw it away. The blower motor is accessible from under the hood. If you have a problem with the blend door, the dash does have to come out. I would first remove the return hose from the core (under the hood) and make sure hot water is circulating through it. If the core is plugged it can be changed from under the hood, although the AC system has to be discharged, parts removed to gain access, then recharged. Good Luck.