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Old 01-28-2014, 11:10 PM   #1
dman1982
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no defrost??? what the heck??

I've been tinkering with my heater and can't get the defrost going...i switched out the the switch panel first, now i have 3 of the 4 settings for the motor, high isn't working now, and the other 3 setting are....i can't get the defrost going...the floor is working really good, and the vents are sorta working but the floor is still going full power....what the heck is going on???
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Old 01-28-2014, 11:19 PM   #2
bnoon
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Re: no defrost??? what the heck??

Have you pulled the piece behind the glove box and see if your blend door is stuck/broken? Usually the default is defrost when it gets broken but I've seen the doors get jambed too due to debris or just plain ol bad luck.
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Old 01-28-2014, 11:39 PM   #3
dman1982
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Re: no defrost??? what the heck??

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Originally Posted by bnoon View Post
Have you pulled the piece behind the glove box and see if your blend door is stuck/broken? Usually the default is defrost when it gets broken but I've seen the doors get jambed too due to debris or just plain ol bad luck.
ive messed with that i was trying to get a pic to load up but its taking forever, that door seems to open as its suppose to, but still no defrost...
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USMC Aviation Ordnance
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84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

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Old 01-28-2014, 11:58 PM   #4
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Re: no defrost??? what the heck??

So you have looked at this part and everything is moving good?
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Old 01-29-2014, 12:49 AM   #5
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Re: no defrost??? what the heck??

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So you have looked at this part and everything is moving good?
ya, the door isn't caught or anything, I've unhooked it and messed with the door and switch panel at the same time.....soooo lost right now!!!
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USMC Aviation Ordnance
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84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 12:54 AM   #6
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Re: no defrost??? what the heck??

If your blend door is moving when changing modes then I would think it should be redirecting air where it is supposed to. Let me ask you this. Did you unhook the piece of all thread and with the truck running and manually push the door and hold it in both directions to see if it went to defrost 100%. Still sounds like the blend door is not either opening or closing 100% so your direction of air changes.
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Old 01-29-2014, 12:57 AM   #7
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Re: no defrost??? what the heck??

Quote:
Originally Posted by rs74 View Post
If your blend door is moving when changing modes then I would think it should be redirecting air where it is supposed to. Let me ask you this. Did you unhook the piece of all thread and with the truck running and manually push the door and hold it in both directions to see if it went to defrost 100%. Still sounds like the blend door is not either opening or closing 100% so your direction of air changes.
I don't think it was running when I unhooked it, and I still have it unhooked
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USMC Aviation Ordnance
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2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 01:05 AM   #8
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Re: no defrost??? what the heck??

Turn it on and manually hold the door itself both ways with the rod unhooked and see if that diverts your air. Just make sure you are getting 100% movement out of the door and it is not just moving 50% or so.
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Old 01-29-2014, 01:07 AM   #9
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Re: no defrost??? what the heck??

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Originally Posted by rs74 View Post
Turn it on and manually hold the door itself both ways with the rod unhooked and see if that diverts your air. Just make sure you are getting 100% movement out of the door and it is not just moving 50% or so.
thats why its still unhooked, when i move the door the air doesn't move
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USMC Aviation Ordnance
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2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 01:12 AM   #10
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Re: no defrost??? what the heck??

Got me then. That is what directs your air.
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Old 01-29-2014, 01:14 AM   #11
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Re: no defrost??? what the heck??

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Originally Posted by rs74 View Post
Got me then. That is what directs your air.
That's what I thought too...tomorrow I'm pulling the dash and seeing if all my vents are hooked up...getting really frustrated with this
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USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 01:17 AM   #12
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Re: no defrost??? what the heck??

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Originally Posted by dman1982 View Post
That's what I thought too...tomorrow I'm pulling the dash and seeing if all my vents are hooked up...getting really frustrated with this
Well I thought about asking that but you should be able to see all of that through where the glove box is. At least if your defrost duct is there. I bought my K30 a few months ago and someone had taken that duct out and it was jsut blowing up under the dash. I had to rob that piece from one of my parts cabs.
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Old 01-29-2014, 01:20 AM   #13
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Re: no defrost??? what the heck??

it might have came loose, but even just coming loose and if the vent was was there just off some it would blow a little something, but we gotta keep in mind that this was working a while back, and at one point it was only the defrost that was working and on full blast...
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84 K10
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My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 09:48 AM   #14
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Re: no defrost??? what the heck??

when i pull on that threaded lanyard is my switch suppose to move?
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Sgt Dennis Heineman
USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 11:03 AM   #15
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Re: no defrost??? what the heck??

I had almost the exact same prob...mine ended up being the vacuum supply line going through the firewall was unhooked.

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http://67-72chevytrucks.com/vboard/s...d.php?t=740291
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Old 01-29-2014, 11:17 AM   #16
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Re: no defrost??? what the heck??

what was it hooked up to? and that was the line all the way to the left right?
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USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 11:22 AM   #17
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Re: no defrost??? what the heck??

alright, thanks i found it....and it wasn't hooked up....where does it hook up to? i think found where it used to go but trying to be sure
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USMC Aviation Ordnance
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84 K10
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My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 11:29 AM   #18
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Re: no defrost??? what the heck??

Quote:
Originally Posted by dman1982 View Post
alright, thanks i found it....and it wasn't hooked up....where does it hook up to? i think found where it used to go but trying to be sure
Sorry for this crappy description, but there's a round thing that looks like a stars wars pod (just out of the photo to the left). Vacuum runs from intake port behind the carb to that round plastic thing then another line runs through the firewall.
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http://67-72chevytrucks.com/vboard/s...d.php?t=740291
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Old 01-29-2014, 12:19 PM   #19
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Re: no defrost??? what the heck??

so then two lines run through the firewall one on each side of the truck?
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Sgt Dennis Heineman
USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 12:31 PM   #20
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Re: no defrost??? what the heck??

Quote:
Originally Posted by mickeykreg View Post
Sorry for this crappy description, but there's a round thing that looks like a stars wars pod (just out of the photo to the left). Vacuum runs from intake port behind the carb to that round plastic thing then another line runs through the firewall.
so then two lines run through the firewall one on each side of the truck?
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USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 01:19 PM   #21
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Re: no defrost??? what the heck??

I went out and took a pic from my 84 K30 454. The vaccuum line comes out of the firewall and goes towards the drivers side to a tee. At the tee one side goes over to the drivers side fenders well vaccuum ball. The other side of the tee runs down to the rear of the intake where there is another tee. One side of the tee goes into the intake and the other side runs the vaccuum back to the transmission. Sorry for the sideways shot my computer would not let me save it after I rotated it.

Hope this helps.
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Old 01-29-2014, 01:46 PM   #22
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Re: no defrost??? what the heck??

Here is how I think mine is supposed to be rigged.



This is how I've rigged it before when I was too lazy to get the right vacuum hose.



One way or the other, feed that guy (that goes through the firewall) some vacuum and see what happens.
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'80 SRW C35 - 355/700R4/4:11/2.5-3/DD
'77 Cheyenne K5 - Roller cam 355/NV4500/205/4:88's/35's/DD

rust repair on the '77
http://67-72chevytrucks.com/vboard/s...d.php?t=740291
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Old 01-29-2014, 01:53 PM   #23
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Re: no defrost??? what the heck??

thanks for the pic, mine does have a T fitting, just one in one out...with that first pic you sent me what setting is that on? or is there a way to set it up from scratch to where i know that its where its suppose to be?
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USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-29-2014, 04:44 PM   #24
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Re: no defrost??? what the heck??

so i put everything back together, the valve that opens for the defrost isn't opening, are those known for going bad? or is that the vacuum not doing its job?
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Sgt Dennis Heineman
USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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