I changed cabin filter still blows cold air what's next
Mercedes-Benz Q&AAsk Your Question
1999 Mercedes-Benz ML430 Question: In my 1999 ml430 when I turn on heat it blows cold air what can I do
Answer #1chickenwing December 09, 2013, 16:16Rookie
Replace the thermostat, it is probably stuck in the closed position.
ReplySeanluv247, December 09, 2013, 20:26Rookie
Where is thermostat
Answer #2Greg's Orange Auto (14643 Answers) , Orange, CA - (714) 361-9386globalhelper December 09, 2013, 16:22Master
could be blend door stuck open
Replychickenwing, December 09, 2013, 18:42Rookie
What is a blend door???
Replyziptie12, December 09, 2013, 20:44Master
It's a door inside the HVAC housing that controls the airflow through the heater core and A/C evaporator , to regulate air temp. Cabin filter - filters air. Stuck closed thermostat would cause overheating. CHECK coolant level first , and make sure the engine is reaching proper operating temp.