Topic Sponsor
2015 - 2020 Ford F150 General discussion on the 13th generation Ford F150 truck.
Sponsored by:
Sponsored by: Worksport

Defroster Question

Thread Tools
 
Search this Thread
 
Old Jan 18, 2018 | 06:57 AM
  #1  
Sweetlou's Avatar
Thread Starter
5 Year Member
5 Year Member
 
Joined: Aug 2016
Posts: 702
Likes: 157
Default Defroster Question

All,

I noticed this morning that when I turn the heat to feet only, my defroster is still on. If I add defroster, more heat comes out of the defroster, but if I turn defroster off and keep feet on, heat continues to come out of defroster.

normal? I’d think not...?

thanks
Reply
Old Jan 18, 2018 | 07:10 AM
  #2  
jp2012's Avatar
Senior Member
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2012
Posts: 707
Likes: 247
From: Indiana
Default

Sounds normal. My '05 and '12 were the same way.
Reply
Old Jan 18, 2018 | 07:39 AM
  #3  
D_D_in_KY's Avatar
5 Year Member
5 Year Member
 
Joined: Mar 2015
Posts: 495
Likes: 118
From: Central Kentucky
Default

Floor modes on most vehicles have a defrost bleed to need the windshield and side windows clear. If the glass were not heated one could get condensate (fogging) on the inside surfaces.
That's another reason why Recirc. times out... to prevent moisture from the footwell being drawn into the HVAC and fogging the windscreen.

Last edited by D_D_in_KY; Jan 18, 2018 at 07:42 AM.
Reply
Old Jan 18, 2018 | 07:40 AM
  #4  
TheGeek's Avatar
5 Year Member
5 Year Member
Liked
 
Joined: Dec 2016
Posts: 345
Likes: 50
From: Indianapolis
Default

I'm a contact lens wearer, so I'm really sensitive to the hot air in the face. I've found there's a little bleed in the windshield defrost vents, but the side defrost vents are on all the time regardless of the setting.
Reply
Old Jan 18, 2018 | 08:20 AM
  #5  
Ricktwuhk's Avatar
Senior Member
Liked
Loved
Community Favorite
Top Answer: 10
 
Joined: Dec 2013
Posts: 14,975
Likes: 6,035
From: SE Michigan
Default

Agree. If it bothers you, throw a towel over the defrost vent.
Reply
Old Jan 18, 2018 | 08:31 AM
  #6  
D_D_in_KY's Avatar
5 Year Member
5 Year Member
 
Joined: Mar 2015
Posts: 495
Likes: 118
From: Central Kentucky
Default

Originally Posted by TheGeek
I'm a contact lens wearer, so I'm really sensitive to the hot air in the face. I've found there's a little bleed in the windshield defrost vents, but the side defrost vents are on all the time regardless of the setting.
Can I ask at what HVAC blower speed you're running?
Reply
Old Jan 18, 2018 | 09:11 AM
  #7  
shortride's Avatar
Okie Coupe
iTrader: (1)
 
Joined: Aug 2007
Posts: 4,702
Likes: 209
From: S.E. Oklahoma
Default

I think it may be a safety thing. In the wrong conditions you would never want the windshield to fog up. I've driven in areas where that can happen very quickly. Of course this is only a WAG.
Reply
Old Jan 18, 2018 | 10:40 AM
  #8  
TheGeek's Avatar
5 Year Member
5 Year Member
Liked
 
Joined: Dec 2016
Posts: 345
Likes: 50
From: Indianapolis
Default

Originally Posted by D_D_in_KY
Can I ask at what HVAC blower speed you're running?
Any speed. Even with HVAC off and the blower on passive.
Reply
Old Jan 18, 2018 | 05:38 PM
  #9  
D_D_in_KY's Avatar
5 Year Member
5 Year Member
 
Joined: Mar 2015
Posts: 495
Likes: 118
From: Central Kentucky
Default

Hmmm! "blower on passive". help me out here! I don't understand your term "blower in Passive".

I have a single zone system in my 2015. When I turn the HVAC Off I can hear the Recirc door move to seal the fresh air path off. Driving down the road at any speed I do not have air flowing into my vehicle....none. Driving with the HVAC ON, Blower setting to the lowest speed the air volume through the HVAC does not change with the vehicle's speed, it stays pretty consistent. Do you have a dual zone system? Does the air volumes change with vehicle speed with the HVAC OFF ? Does the air volume change with the HVAC ON? IF IT DOES !! Is the air temperature through the system changing when you adjust the blend door(s) from full heat to full cold? or does it remain the same, i.e. close to outside ambient or a heated condition?
Reply
Old Jan 18, 2018 | 06:15 PM
  #10  
RL1990's Avatar
5 Year Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2016
Posts: 3,263
Likes: 1,177
Default

Most systems bleed a small amount of air to the defroster vents on the floor setting, some more that others. It keeps the windows from fogging and prevents ice build up by keeping warm air flow on the glass. On my Acura you can barely feel the air coming out but Ford has much more air flow. The F-150 also defrosts the windshield quicker and clears more glass area. I like how the truck's defroster vents span most of the dashboard top. On my Acura it's mainly in the center portion of the dash so the corners of the windshield take a long time to de-ice.
Reply



All times are GMT -4. The time now is 04:23 AM.