Disconnect the negative battery cable.
== ==
49.99 to 69.99 where I work!
Heater CORE, not coil. The core is plugged and needs back flushing or replacement.
Your local auto parts store has replacement ends for that. They also have the tools to help you remove the fitting from the heater inlet/outlet tube.
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See the Related Link for "1996 and Up Water Pump Replacement Procedure" to the right for the complete walkthrough with pictures.
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There is no such thing as a 1997 dodge saturn! Try again.
http://www.autozone.com/addVehicleId,2340701/initialAction,repairGuide/shopping/repairGuide.htm?pageId=0900c152800bca17 Have fun. Stu