2003 was a changeover year for Ford, so it's not clear if the system you are comparing to is the old or new. There are two different plenum boxes used by Ford on the Explorer in the year ranges you are questioning. Most likely both the 03 and 04 have the newer style box. Both the old and new designs have problems. Check the engineering report on the later model Explorer's on heatertreater.net. There are pictures of both systems that will help you identify which one you have and information on the fail modes and fix.
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where to find heater resistor 2004
The 2004 Ford Explorer has 44.5 cu.ft. of cargo capacity with all of its seats in place.
how do you remove the tourque convetor botls to flex plate on a 2003 explorer
The thermostat on a 2004 Eddie Bauer Edition Explorer 4.6L V8 is located in the top heater hose. It is in the end that is attached to the water pump.
Under air box hose .Right side of vehicle .Should have 4 heater hoses going to it and a small vaccum line .
I have a 2004 Ford Explorer and the heat does not work, but when i try to turn the control valve to heat it makes a clicking noise. How do i fix it?
National Geographic Ultimate Explorer - 2003 Rat 1-14 was released on: USA: 22 March 2004
National Geographic Ultimate Explorer - 2003 Tempests from the Deep - 1.6 was released on: USA: 4 January 2004
National Geographic Ultimate Explorer - 2003 King Rattler 1-8 was released on: USA: 8 February 2004
National Geographic Ultimate Explorer - 2003 Elephant Power 1-12 was released on: USA: 13 March 2004
National Geographic Ultimate Explorer - 2003 The Lost Gold of the Republic - 1.47 was released on: USA: 23 April 2004