no defrost??? what the heck??

[dman1982]

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???

[bnoon]

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.

[dman1982]

Originally Posted by bnoon

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...

[rs74]

So you have looked at this part and everything is moving good?

[dman1982]

Originally Posted by rs74

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!!!

[rs74]

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.

[dman1982]

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...

[dman1982]

when i pull on that threaded lanyard is my switch suppose to move?

[mickeykreg]

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

[dman1982]

what was it hooked up to? and that was the line all the way to the left right?

[dman1982]

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

[mickeykreg]

Originally Posted by dman1982

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.

[dman1982]

Originally Posted by mickeykreg

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?

[rs74]

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.

[mickeykreg]

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.

[dman1982]

so then two lines run through the firewall one on each side of the truck?

[dman1982]

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?

[dman1982]

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?