Heater not working

2003 FORD EXPLORER
200,000 MILES • 6 CYL • 4WD • AUTOMATIC
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FROZEN IN MICHIGAN
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Just blowing cold air. I already drained and replaced coolant, flushed lines, blender actuator and temp control valve. Gauges are working and it doesn't overheat. Now what?
I am freezing please help.
Dec 9, 2021 at 1:48 PM
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ASEMASTER6371
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Good morning,

I would start by flushing the heater core. Remove the two inlet hoses and use a garden hose to flush the core back and forth. You need a good even flow in both directions with no dirt or debris.

https://www.2carpros.com/articles/car-heater-not-working

https://www.2carpros.com/articles/replace-heater-hoses

If that does not work, most likely the heater core is the issue and must be replaced

.https://www.2carpros.com/articles/replace-heater-core

Roy
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Dec 9, 2021 at 6:34 PM
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FROZEN IN MICHIGAN
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Okay, I've checked and flushed coolant, thermostat, heater core, no coolant or water leaks, replaced control valve and blend door actuator, checked resistor switch and blower. No luck, still freezing. Oh and no sweet smells or overheating.
Dec 17, 2021 at 2:12 PM
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ASEMASTER6371
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Okay did you do the voltage checks I asked you to do?

Roy
Dec 17, 2021 at 7:20 PM
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FROZEN IN MICHIGAN
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I have not, don't recall you saying anything about that. Voltage to what?
Dec 18, 2021 at 10:08 AM
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ASEMASTER6371
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Check for voltage to the blower motor with the key on to be sure there is power.

There should be voltage on both sides of the connector.

Roy
Dec 18, 2021 at 10:18 AM
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FROZEN IN MICHIGAN
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Oh, I will check that out of desperation, but the blower seems to be working fine.
Dec 18, 2021 at 10:23 AM
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ASEMASTER6371
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Is there good air volume to the cab?

Roy
Dec 18, 2021 at 10:24 AM
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FROZEN IN MICHIGAN
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Yes it is just cold not heat.
Dec 18, 2021 at 10:26 AM
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ASEMASTER6371
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The hoses to the heater core. How do they feel to the touch? Are they both hot?

Roy
Dec 18, 2021 at 10:28 AM
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FROZEN IN MICHIGAN
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Yes, I checked those too.
Dec 18, 2021 at 10:31 AM
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ASEMASTER6371
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How did they feel to the touch?

They should be hot. One hotter than the other.

Roy
Dec 18, 2021 at 9:20 PM
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FROZEN IN MICHIGAN
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They are both hot. My brother wants me to change out the thermostat even though it isn't overheating and check fuses. What do you think?
Dec 18, 2021 at 10:22 PM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
No, if the hoses are hot then it is not the thermostat.

It is coming down to the heater core itself.

https://www.2carpros.com/articles/replace-heater-core

I attached a YouTube video below for you to view. This is how I do the repair to save a bundle of time.

https://www.youtube.com/watch?v=Y4G6ljTEL9k

Roy
Dec 18, 2021 at 10:39 PM
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