How do you troubleshoot a heater on a 1999 Ford Taurus?

Answer 1

See "Related Questions" below for much more about trouble-shooting Taurus / Sable heater problemsAnswer

Sounds like you have a heater not getting hot, right? There is only two possibilities.

One that there is a coolant problem, and the others is a temp blend door problem.

First check the coolant in the coolant jug. Is it full? Is it rusty? The most common thing that goes wrong with these cars, is severe rust in the cooling system which clogs up the heater core, and eats the impellers off the water pump. This causes no coolant flow through the heater core and very little flow in the cooling system in general.

Unfortunately, if this is the case, you will not be able to flush the heater core effectively. The passages are just too small. The heater core will have to be replaced. The water pump will probably be needed as well, since the impellers are probably just about gone.

The other most common thing is a warped temperature stratification / blend door in the heater case. This door can bind up with the blend door and cause either no heat or no AC, depending on what position the door is stuck in. This is such a problem that Ford designed a new door design. The part number of the new stratification door is 3F1Z-19D842-AA. These are the two biggest issues with that car. Hope this helps.

ANSWER

Replacing the blend door is an involved process with the Ford door. A less expensive and easier alternative is the HeaterTreater Taurus blend door kit. The plastic door is replaced with metal that will outlast the Taurus. Check heatertreater.net for diagnostic information and an inexpensive fix.