Typically, the dashboard needs to be removed, and the A/C system needs to be evacuated. Your A/C module needs to come out before the heater core can be accessed. Your heater core should be located on the front passenger side under the dashboard area.
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To put it mildly, the heater core is fairly buried in the bowels of the dash. It lives inside the HVAC case, alongside of the A/C evaporator, and the HVAC case isn't really visible as there are many underdash items blocking its view. To give you an idea of how remote is it, the going rate for labor time to remove and replace the heater core is about 6 hours. And this DOES NOT include the time it takes to remove and recover the refrigerant or evacuate and recharge the A/C system. The heater core has a list price of about $390, and if the labor rate in your area is $100 per hour, the cost of replacing it can easily top $1,100.00 once you include antifreeze, new hoses, refrigerant and shop supplies.
〉 Answered on Jul 23rd, 2011 by Kerri Papajohn, Marketing Director at USA Sealants, Inc.
Heater cores are located between the engine and the cab of the vehicle. If you need to gain access to it,you may need to take apart some of the dash.
〉 Answered on Jul 23rd, 2011 by Suzanne Grego, Technician at City of Philadelphia Fleet Management