It is under the hood. It is on the fire wall, just follow the heater hoses. Testing is done by turning the heat on and feeling the hoses to the heater core, if they're cold the heater valve is suspect and at that mileage they have a high failure rate, go to Realoem. Com for the price and availability of your heater valve.
Monday, June 1st, 2009 AT 8:32 AM