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Rear hvac no hot air


Apexmaster

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02 Ford explorer
Hello
Yesterday we noticed when I turn on the rear hvac system for 2nd and 3rd row it only blows cold no matter where I place the arrow on heat range.
Any idea what might cause this?
From videos online it shows expedition and explorer have rear independent blower in trunk area.
 


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Tshaw88

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05 Explorer Eddie Bauer
Hello
Yesterday we noticed when I turn on the rear hvac system for 2nd and 3rd row it only blows cold no matter where I place the arrow on heat range.
Any idea what might cause this?
From videos online it shows expedition and explorer have rear independent blower in trunk area.
what year is it?? most with rear hvac controls will also have a second heater core back there as well. there are coolant lines that branch off near the water pump and run down under the vehicle along the passenger side to the rear heater core. sounds like rear core is clogged.
 




Apexmaster

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what year is it?? most with rear hvac controls will also have a second heater core back there as well. there are coolant lines that branch off near the water pump and run down under the vehicle along the passenger side to the rear heater core. sounds like rear core is clogged.
Sorry it's 2003 v6
 




Apexmaster

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what year is it?? most with rear hvac controls will also have a second heater core back there as well. there are coolant lines that branch off near the water pump and run down under the vehicle along the passenger side to the rear heater core. sounds like rear core is clogged.
How can I check if they are clogged? And if yes how to unclogged?
 




Tshaw88

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find the two hoses running to the heater core, with the car on and at operating temp with the heat on its highest setting grab both hoses one in each hand, if both hoses are cold then the diverter probably is stuck shut, if one is so hot it feels like your hand is on fire and the other is stone cold its clogged, undo both hoses, the red hot is the feed line the colder one is the return line, the return line should be slightly colder than the feed line. attach a garden hose to the feed line, leave the return unplugged and run water through the heater core with the garden hose. it will flush the rust and crap out.
 




Punchy77

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2005 explorer Eddie Bauer
Hello
Yesterday we noticed when I turn on the rear hvac system for 2nd and 3rd row it only blows cold no matter where I place the arrow on heat range.
Any idea what might cause this?
From videos online it shows expedition and explorer have rear independent blower in trunk area.
Oh I’ve had this problem, you might want to check the wires to the dials if they are connected properly. I took down the the whole thing on the top there where the dials are to put in some custom lights and after putting it back up I realized the rear heat wouldn’t work. Took it back down and fixed the wire connection to the dial. While up there I noticed all the wires were not held on the best, either someone has been up there before me or it’s like that from factory. Best way to get up there is to remove the panels with a flathead screwdriver as a pry tool. Or if you can find a more professional way, do that, the plastic is brittle and can break easily.
 




Tshaw88

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unless he took it apart to do somthing similar, his dials are probably still connected.
 




Punchy77

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unless he took it apart to do somthing similar, his dials are probably still connected.
Yeah fair point. Unless he was driving extremely rough there would be no other reason for them to get disconnected
 




Apexmaster

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So I removed rear plastic cover over rear hvac. I let engine warm up. I do feel hot water in pipes.
So on my car . You can control the hear range from driver seat and from 2nd row. But always cold air.
Where is switch or arm that makes it cold to hot? Is it in engine bay or rear hvac?. I did see photos if one a white box with gears and his gear were broken. I do see the white box on mine but its between hvac and fender. It look like you need pull out entire hvac to get to it.
When I turn heat range knob either from front or rear I do not hear any noise in the hvac like switching from hot air to cold air. Should something be changing in back??
When I rotate heat range know for front hvac hot to cold I do hear something in dash
Also what if 1 hear control knob is set on cold and 1 on hot what eould the hvac blow??
20201122_083435.jpg


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20201122_083456.jpg
 




RickOTR

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Try this, very common on these trucks...
https://www.amazon.com/dp/B07D2JPW9H/?tag=serious-20

edit: there was a write up somewhere on the forum but I can't seem to find it.

oooops here ya go...

 




RickOTR

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Rear AC Blend Door Actuator Gear.JPG
 








Apexmaster

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Try this, very common on these trucks...
https://www.amazon.com/dp/B07D2JPW9H/?tag=serious-20

edit: there was a write up somewhere on the forum but I can't seem to find it.

oooops here ya go...

Is the part that switch from hot to cold??
 




Apexmaster

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Try this, very common on these trucks...
https://www.amazon.com/dp/B07D2JPW9H/?tag=serious-20

edit: there was a write up somewhere on the forum but I can't seem to find it.

oooops here ya go...

I think if this was my issue I would be hearing grinding or something?. Where is this actuator located? I think they said in back of hvac. But they do not say how to get to it or remove the entire hvac. Is there a way to get to it without unplugging hoses?
 




RickOTR

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Remove the two bolts holding the housing on, it's on the backside. You will see it when you pull it out. You do not have to disconnect any of the lines. I have the center console, but the rear controls on yours is similar. I never had a click or any noise on mine. It was just plain dead.

Check out the link in post #10. Has lots of pics to complete the project.
 




Apexmaster

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Remove the two bolts holding the housing on, it's on the backside. You will see it when you pull it out. You do not have to disconnect any of the lines. I have the center console, but the rear controls on yours is similar. I never had a click or any noise on mine. It was just plain dead.

Check out the link in post #10. Has lots of pics to complete the project.
Sorry I think its bad link
 




Apexmaster

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Sorry I think its bad link
Cool I will unfortunately in about 30min remove actuator and inspect it.
I'm also dealing with rear differential noise. Once I hit 55mph I get a winding noise. But when I get off the gas it get quieter. Im pretty sure its pinion bearings
 




Apexmaster

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Ok here is my actuator... same thing small gear is chewed up however its barely spinning big one. Once I connect it and rotate heat range it did start working and spinning shaft but it never stops it keeps rotating either left or right until I change heat range. Im not sure if its normal. Either way this one is out and picking up new one in 2 hrs. So when I get new one. How am I supposed to know what setting it is on. My car is blowing cold but how is actuator set?
I just called autozone they cant find this part by part number given. Looking on Amazon same thing lots of other ones which look like it but output shaft different
20201122_155827.jpg


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20201122_155819.jpg
 




Apexmaster

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Ok here is my actuator... same thing small gear is chewed up however its barely spinning big one. Once I connect it and rotate heat range it did start working and spinning shaft but it never stops it keeps rotating either left or right until I change heat range. Im not sure if its normal. Either way this one is out and picking up new one in 2 hrs. So when I get new one. How am I supposed to know what setting it is on. My car is blowing cold but how is actuator set?
I just called autozone they cant find this part by part number given. Looking on Amazon same thing lots of other ones which look like it but output shaft different
View attachment 324592

View attachment 324591

View attachment 324593
I found this one but output shaft is not D shape like mine. This looks like the first actuator I pulled out to control the foot or ceiling range. It had shaft like that shape

Screenshot_20201122-160232_Amazon Shopping.jpg
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.








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