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2000 Chrysler 300M Question: Not much heat in cab 2000 300m.

 

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mas1487us, 3.5L V6, North Fort Myers, FL, November 15, 2010, 11:32
 Rookie

on our 2000 300 M ,,,How do I run a diagnosis check on my heat /ac system. I have not much heat in the cab. Engine temp is fine. Heater doesnt blow nearly as hot as it could.

mas1487us@yahoo.com

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  • Answer #1

    November 15, 2010, 13:57
     Master

    Check the coolant level, drive belt tension, vacuum line connections, electrical connections, radiator air flow and fan operation. Start engine and allow to warm up to normal temperature.
    WARNING: DO NOT REMOVE RADIATOR CAP WHEN ENGINE IS HOT, SEVERE PERSONAL INJURY CAN RESULT.
    If vehicle has been run recently, wait until engine is cool before removing cap. Squeeze the radiator hose to check temperature, and for pressure in the system. If the hose is very firm, allow time to cool down. Place a rag over the cap and turn it to the first safety stop. Allow pressure to escape through the overflow tube. When the system stabilizes, remove the cap completely.

    MAXIMUM HEATER OUTPUT: TEST AND ACTION
    Engine coolant is provided to the heater system by two 3/4 inch inside diameter heater hoses. With engine idling at normal running temperature, set the control to maximum heat, floor, and high blower setting. Using a test thermometer, check the air temperature coming from the floor outlets.
    TEMPERATURE REFERENCE TABLE Outside air
    (Ambient) Temp.
    Fahrenheit
    60° / 70° / 80° / 90°

    Floor Vent Output temp
    Fahrenheit
    144° / 147 ° / 150° / 153°
    If the floor outlet air temperature is insufficient, . Both heater hoses should be HOT to the touch (coolant return hose should be slightly cooler than the supply hose). If coolant return hose is much cooler than the supply hose, locate and repair engine coolant flow obstruction in heater system.
    POSSIBLE LOCATIONS OR CAUSE OF OBSTRUCTED COOLANT FLOW
    Pinched or kinked heater hoses.
    Improper heater hose routing.
    Plugged heater hoses or supply and return ports at cooling system connections, Plugged heater core. Air locked heater core.
    If coolant flow is verified and outlet temperature is insufficient, a mechanical problem may exist.
    POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT HEAT
    Obstructed cowl air intake.
    Obstructed heater system outlets.
    Blend door not functioning properly.
    Low coolant level
    Air locked heater core or air in cooling system
    TEMPERATURE CONTROL
    If temperature cannot be adjusted with the TEMP knob/button on the control panel, the following could require service:
    Blend door binding.
    Faulty blend door actuator.
    Improper engine coolant temperature.
    Faulty A/C Heater Control.

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    mas1487us, November 15, 2010, 14:29
     Rookie

    Engine is full of coolant and belts hoses ect all in good condition. Engine reaches op temp (180)within 3 mins driving. Cooling Fan,Belt condition, tension, air intake on cowl all good. I doubt heater hoses can be routed any other way, right side rear of engine to R side, left side rear cyl head to left side at firewall. Heater Core tubes are clear inside and out.(no idea if core is air locked)...Air bleed valve bled to vent cooling system.
    Floor, dash Outlets are clear, blend door makes a different type sound when changing temp and other dash funtions work perfect. Blower speeds are great.
    Temp adjusted #'s change as well.
    Both heater hoses are hot. Left side facing firewall is hotter than right side. Just like on any heater core system vehicle.

    How can I diagnose blend door acuator? How can I check for codes on this ac/heat system?

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