Thanks, I'll check it out...

@mike-rabaut 

Hi Mike

Could you post pictures of the defroster outlet slots in the dash on your truck?

Especially looking down at the ends of the slots, and /or up at them from below?

You have me interested and wondering if yours (1940) are actually the same as mine (1946).

It seems strange to me that the attachment holes wouldn't have been predrilled.

Also, I'm having a hard time figuring out what the parts listed in the '29-'41 parts book really are.

Inlets?  Outlet adapters?  Deflectors?

Hope you are understanding it better than I am.

I'm thinking your best bet might be looking for someone parting out a 1940 truck in some northern area, where defrosters would have been commonly installed.

Ole,

I can't get a handle on it either, so....sorry back,  I crawled under my dash and took some pictures...  It didn't show much then I realized too much light was coming through the vent opening.... So I taped it closed and re shot.....  And what do you know....  Something is there.......  I ran a ice pick up in there and there is a dent.... I figure it's the hole for a screw....  If so, what size?????   What does yours use?  There is a guy on ebay who sells Harrison heaters.  He says he has the vent inserts and stuff...  Ill ask him...  Maybe....

@mike-rabaut 

Hi again

Your outlets look exactly like mine.  Same size, same shape.

That should mean that any parts from trucks from 1940 to 1946 should be the same (and maybe 1940/41 cars?).

The screws look like the self tapping sheet metal kind with a sharp point and a pretty long thread pitch.

I'm thinking a good rap on a very sharp awl, or some such thing, just to open a small hole for the point of the screw may be all you need.  Depends on the thickness of the metal.  You may have to drill to the inner diameter of the screws if the metal it too heavy.

Good idea on where to look for parts too.  👍

PS

You can see most of the end of one of the screws in my third picture in my earlier post.

The pointed end is just out of sight.

Finally found way to get up there..... I found that Sheet metal screws won't work....  The metal is too thick.   But the holes are the same type that the metal side panels use for their #8 truss screws....  Just unthreaded....   They look like there for  a #6  but the head might be too small for the vent flange.  When I get a vent, I'll know.  Im guessing they drilled all the holes for the sheet metal the same to use the same type of screws...  A #8 .

Ole,

Well I finally have my heater vents installed. I found a set that's matches the opening I have on Ebay. I tried a number of different screw, both machine and sheet metal and found that because the holes in the dash were not tapped, I would uses the sheet metal screws as suggested by many here and found that the only size that fit the vents were a #6 1/2 inch sheet metal screw. I was concerned that the netal would be too thick to use sheet metal screws, possibly breaking them off, but I found that not to be the case. I was concerned about the screw head being too small but a #6 was perfect. The vent hose is 1-1/2 inch and made of some kind of paper. There is no indication whether the vents point to the back or down.... I'll deal with that later...

Thanks to all...

Mike

@mike-rabaut 

Excellent!

Looks like you now have EXACTLY what I see under my dash.

Even the size and type of screws are the same!  👍

@mike-rabaut 

Regarding the 1-1/2 inch "paper" hose.

I've been semi looking for some to replace mine.

I believe hoses are being produced in a material similar to the original, but seem to be out of stock when I'm looking.

I do think they are out there though.

@ole-olson 

This is what I got.....

Seems to fit.  It's 3 ft long... 1-1/2 dia ....   I'll see if it's long enough for the two vents when I install the heater.

Hi Mike

That looks like it should be great fit.

What is it made of?

I had been looking for something like this, but it never seems to be available when I'm looking (still isn't):

Ya, I know, is says it's for another breed.

But it looks alright.

I found that 3 ft of hose is long enough to connect to the defrost vents as long as stretch it carefully.   It just fits. 

The next question is, do you install the heater while the glove box is installed or install the glove box after.   I left my glove box out to have better access to installing the heater and now I can't get it back in.

Mike

What's interfering with it going back in? I had the liner out of my 38 when I put mine in and no trouble getting the liner back in.

The glove box liner goes in from the back. I installed a fresh air heater and it interferes with the liner going back in.  Before I pull the heater, and then try to insert the liner,  I wanted to find out if the heater goes in after the liner.

Mike

I've not heard of having to remove the heater to pull the liner but I've not done a '40 either. The reason I asked about what's interfering with the liner going back in is your comment about barely having enough hose. If the problem is not being able to clear the hose with the liner you might have the defrost ducts mounted backward. Each duct inlet should be pointed roughly in the direction of the defroster. If they're mounted backward it'll take a lot of hose to make the connections and it's possible it might be in the way of the glove box liner. Not being there to see the issue this is just a guess. When I was putting the heater/defroster in my 38, I was laying under the dash checking the fitment of everything because nothing was marked as to it's proper location. I discovered that the ducts will "fit" either side but are the best fit (and make more sense) with the inlets pointing toward the defroster.

@tiny 

I checked for that before I installed the defrosters ... They are exactly the same.   Unless I'm have the wrong ones....

The defroster tubes all seem to come in 3 ft lengths.... When you can find it....    So it's just barely long enough when cut in two sections....  But it does fit.

I'll go back under today and look at it again...

Thanks for the comment.

Mike