The Stovebolt Site Forums The Shop Area Interiors defroster problems

Now that I have a windshield installed, and the interior trim, I thought I'd test the heater/defroster. The heater blows lots of air, but moving the lever to defroster position makes little difference. A very little bit of air comes out the defroster vents, but most is still coming out the floor vent. I checked all the hoses, and everything seems to be hooked up well. I removed the cable to see if I could get more movement from the flap that directs the air, but still no change. I know the hoses are clear, and the fan is obviously doing a good job.

Does anyone know just how far the defrost lever should move? I'm wondering if somehow the flap is running into something like a screw inside that isn't letting it move far enough. I really don't want to remove the heater, although I could remove the little part that has the defroster hoses and flap. It's just attached to the main body by four screws, two of which are easy enough to get to (once I removed the glove box to get a look at things.

Tim

You might want to post a photo of your heater, so we can see the style.

Perhaps the "flapper" has slipped on its pivot-post/rod?
Or, maybe the flapper has been bent?

Here's a photo of the heater before installation. I can manage to remove the top section, that has the two defroster outlets and the flapper, without removing the heater. When the lever is in the heat position I can see that it covers the area leading to the defroster vents, but I can't see what happens when it's in the defroster position.

tim

I dimly remember that either there might have been a rubber bumper/seal on the lip of that flapper, or, that someone reported putting a seal on that "lip".

The might have used a heat resistant tube with a slit cut from end-to-end?

Maybe I am dreaming?

Well, I removed that top section of the heater, and found a tab sticking out that the flap ran into. So I bent it out of the way, and now the lever swings what seems to be the full travel. So I hoked everything back together, and now when I swing the lever by hand as far as it will go I get air from the floor vents (both of them), and when I swing it to the defrost position I get air coming out ot the floor vent closest to the driver, but not the other one and not the defroster.

Just how far should this lever swing? At the moment it goes way past where the cable clamp would be (I have that temporarily removed). I'm wondering if the flap should only move so far, and I'm moving it past where it should go.

Maybe the flap needs to be lengthened a little so it reall seals off the floor vents.

Hard to describe what I'm talking about without a drawing. I'll see if I can put one together.

Tim

Here is a drawing attached.
The Tab is a stopper for the defrost damper door. I guess so the damper doesn't hit the squirrel cage.

The defrost in these old heaters are not high tech.
It seems to me that when the damper door is open for defrost it is designed to split the floor air and the defrost air.

It would be nice to direct all the air to the defrost tubes but you would some how have to close off the floor air output..

xfiles

Well, the defroster problem is solved. Turns out it had nothing to do with the flap, or the control arm or any of that.

While I was working on it this evening, I pulled off the inner windshield trim piece, and got defrost air! Apparently the new windshield rubber is thicker than the old and was blocking the flow of air. So I removed the thin strip of metal that goes against the rubber by the defroster vent, bent the vent part out a little more to gain clearance between the rubber, put it back together and the defroster worked!

So now I get to reassemble everything I took apart, although at least I took the opportunity to put hose clamps on all of the hoses, so nothing is going to come loose.

Thanks to all who helped with this.

Tim

Did you install new vent hoses? If so where you able to get them? Thanks

New vent hoses were from Jim Carter.

Tim

Good find!
I was ready to suggest that you had squirrels.

We do have squirrels. Also armadillos, raccoons, and groundhogs. I've spent the last two weeks trying to catch the groundhog that is bothering my wife's garden,, and so far have caught two BIG raccoons, and two of the biggest armadillos I've ever seen.

However, none of them seem interested in my old truck, although the pack rats like to get in everywhere.

Tim

Reece's Pieces for ground hogs. I am not kidding! I had a homeowner who caught 3 in a row either coming from or going to his garden. He did not have the heart to kill them, but he wanted them to never return, so he called me.
Squirrel cage,squirrel cage, squirrel cage. (Just in case the moderator is watching )

bartamos


(Just in case the moderator needs to know who to admonish.)