1991 Ford Tempo no heat

Check and test the blower switch, blower motor relay, blower motor resistor and blower motor

Is this the first cold weather for you and this car? Do a search of this tempo forum key word heater/blower for lots of info. These cars are notorious for burning out wiring plugs/switches for the heater fan! Ford should have put a power relay right at the blower instead of wiring high amps all thru the system! But it also could be your blower is dead. Its under the glove box area. Test for voltage at blower. Usually the motor brushes wear out. The air controls are vacuum operated and it all feeds behind the central dash button box! See if you hear the blend doors operate when push buttons! The vacuum is fed by a small plastic line from the firewall which is right behind engine! If your blower motor is good you can cheat by running 12 volts directly to it using a household wall switch!