It depends on what is wrong with it. First make sure there is vacuum going into the cab from the engine compartment.
If the problem is switching between Defrost and Vent, the problem is most likely a vacuum issue since this function is vacuum controlled. If the issue is lack of heat, most likely the problem is with the heater core or blend door. Check HeaterTreater.net for pictures and diagnostic information...and a blend door fix.
See "Related Questions" below for more about Taurus - Sable heating systems.
No one knows if:The heater is NOT blowing - or blowing on high speed only, or... The heater IS blowing, but the air is NOT hotEither way, the "Related Questions" below will get you started
The Ford Taurus is famous for having leaking heater core. It is located on the passenger side inside the passenger compartment and inside the dashboard. It costs about $1000 to get a mechanic to fix it.
2001 dodge ram 1500 ac and heater flow regulator switch does not work. works only on defrost. How to fix?
You cannot "fix" it. But you can replace it in about an hour.
1999 Ford Taurus. System Adaptive fuel too lean banks 1 and 2. How can I fix these.
replace the brake line and then bleed the brakes
You could always take it to the shop You could always take it to the shop
Replace it with a new one.
Take it 2 a mechanic. :D
Trouble code P0500 means: Vehicle Speed Sensor A