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sentinal02 12-06-2004 10:22 PM

Better Heat in a YJ!
Ok, we’ve all seen the posts about making the heat come out the A/C vents. And I’m sure anyone who lives in the season climates has said at some point that they wish they could adjust the heat a bit better. The YJ vents just aren’t located in the ideal spots for human comfort. Sure your feet are warm and the windshield takes 5 seconds flat to defrost, but even after the air in the cab has warmed up a bit your steering wheel is still ice cold and you’re alternating hands on top of the dash to keep them warm. Well now you don’t have to. Incidentally, this mod might work on a CJ but I won’t swear to it. The idea should work, but I don’t know about the dimensions.

After two winters of frostbitten fingers holding onto the wheel, I decided to get smart. I said, why can’t I design some sort of vent cover to deflect the air out towards the back of the jeep once the windshield has defrosted? The answer was I could. Here’s what I came up with.

Now that you’ve seen it, you’re probably saying why didn’t someone think of this sooner? I know I did. This simple piece of sheet metal makes all the difference driving in the cold. Having done it I’m quite surprised some of the aftermarket companies haven’t done this before. Perhaps they’ll come up with something if this idea takes hold. But until then, here’s how to make your own. All you really need is a couple flat, straight edges to make the bends with, a drill and 9/64” bit, and a pair of tin snips.

Ok, first thing to do is run out the steel supplier or hardware store and pick up some sheet metal. I used 16ga sheet simply because I had a bit of scrap that I was practicing welding on, but I found this to be a little thick to cut easily with the snips. 18 to 22ga would probably be a better choice if you’re buying it from the supplier. Incidentally, Home Depot sells smaller sheets so if you don’t have a steel supplier locally check there. Most suppliers will have odd sized cuts though so it might be cheaper there. Anyway, while you’re out, pick up four 6-32 round head screws about 3/8 to 1/2” long, with matching nuts and washers. Might as well grab the paint of your choice too while you’re there. Don’t forget the primer if the paint calls for it when painting metal.

Ok, now that we’ve got our goodies, back to the shop. Pull out your tin snips, your ruler and combination square (or any other method you have for finding a 45° angle.) If you’ve got a table saw or power miter saw you can fit either one with a metal cutting blade to make the larger straight and miter cuts a lot easier. Just be sure to suck as much sawdust out of the traps as you can before starting so you don’t start a fire with the sparks. Now, first step is to layout the deflector shield itself. Go out to the jeep and measure the length of the vent that you want to cover. I went just shy of full length with mine because I have the clinometer mounted in between the two vents and if overlaps them by about half an inch. So mine are 12.5” long instead of the 13” that the vents actually measured. You’re might be different though so be sure to measure first. Since the shield just sits on the top of the vent opening though, you could easily make it only cover half the vent so you get air to both the windshield and out toward the cab. I did notice that the outer half of the vents blew harder than the inside so you might want to check yours with the blower on to be sure you get what you want. Anyway, once you decide on the length, add 2-1/8” to that length. That will cover the side folds. The width of the shield should also measure 2-1/8” wide. So what you have is a rectangle of stock 2-1/8” wide x (your desired length + 2-1/8”). Got it? Good. Scribe the rectangle on the stock and find the center of the short sides and mark them. Measure in 1-1/16” from each end and draw a vertical line across the width of the rectangle. Now, take your square and draw two 45° lines from each edge of the rectangle where you just drew those vertical lines to the center tic marks you made in the step before. These width measurements are set to give you a 45° right triangle with legs that are exactly 1-1/2” long because your dash pad is 3” wide. In either the up or down position you’ll either cover the windshield half where the vent is, or the cab half to let air hit the windshield in defroster mode. You should get 4 lines total looking something like this:

Those inner vertical lines represent our bend lines while we’re going to cut along the 45’s we just made. Cut out the rectangle first to make things easier to handle and then cut along the 45’s to remove all the waste. Once you cut things out it should look like a two way arrow.

The next step is to pick one edge to be top and one to be the bottom. Doesn’t really matter which, but I like to pick the cleaner edge as the top. This will be the edge most visible to you once installed. Once you decide, measure down along the vertical width lines 1/2” and scribe a line across the entire length. This will be another bend line to create the piece that will force the air toward you. From that point you just found, mark a 45° line back toward the top to intersect the leg of the triangle. This little piece will allow the two bends to fit together nicely. Take the snips and cut along that vertical line to free that long bend line up from the triangles on the end. Now cut along the little 45 line and remove the little triangle you just cut out. You should have something that looks like this:

sentinal02 12-06-2004 10:27 PM

Part 2
Now comes the tricky part: making the bends. The best way to do this is with a sheet metal brake, but if you don’t have access to one, you can make do with a table edge, a short 2x4 or other board and a couple clamps. Line up the long bend line you scribed a half inch in from the top with the edge of your table, with the ½” piece on the top of the table. This will give you better leverage than going the other way. Place the board on top to sandwich the metal between the two and clamp the board down tight. If the little tabs on the ends get in the way of the clamps, you can bend them now and hammer them back straight after you’re done. I made the mistake of making a 90° cut in the above steps so mine didn’t have the tabs to cause problems. Here’s my setup:

Once things are tight, take another board and use it to bend the overhanging part down evenly to 45°. The board is to distribute the force evenly to avoid warping the metal pushing in one place. This is where a combo square with a 45° edge and a level bubble come in handy.

When the bubble reads level, you’re at 45°. This one isn’t quite there yet. That angle isn’t too critical though so as long as you’re close you’ll be ok. The closer you are the better it looks though. Once you’re satisfied, remove the piece from the clamps and bend the little tabs back in line with the triangles if you have to. Now, set things up in a vice or back under the clamps with the triangles on the ends being bent this time. The vertical lines are your bend lines this time. Bend the ends in to meet the 1/2" lip you just bent so what you end up is this:

Note that yours shouldn’t have that little triangle piece missing on the left side. That’s what happens when you make a 90° cut instead of a 45. My mistake. Feel free to go this route if you like it though. ;) No real harm done. With both ends bent it should look and sit something like this:

Starting to look like it might work huh? All that’s left is to make the pivot arms that will attach to the dash pad. They’re a bit simpler.

First make a pair of rectangles 2-1/4” long by 1” wide. One for each side. Next, measure in and make vertical lines across the width at 1-1/4”, 1-1/2”, and 1-3/4” in. Split the width in half with a line running the full length of the rectangle at 1/2”. What you should have when cut out is this:

The longer piece is 1/2" wide by the full 2-1/4” long. The smaller square is 1/2"x1/2”. The mark at 1-1/2” was for a centerline to show us where the hole for the screw should be. I chose to round off the ends (penciled in here) to avoid sharp corners. To round them off, snip the bulk of the corners off and file or grind them down the rest of the way. Now, mark a center on the 1/2” tab and drill a 9/64” hole. This will be to mount the shield to. Also, mark a center line on the long part of the arm (1/4” from top or bottom) and drill two 9/64” holes between the tab and the longer edge. Keep them somewhat even, but the spacing isn’t really critical. 3/8” from the edge and from the tab would be fine. These will be holes to mount the arm to the dash. Don’t put them past the tab though because the shield will block them out and it’s easier to mount the shield to the arms before mounting the arms to the dash (trust me I know :D ). Now, put the long part of the arm in the vice and bend the tabs out to a 90° angle. Remember to mirror each arm when making the bends to make a left and right side. What you should have is this:

These have been painted and the one on the left is shorter to clear my clinometer, but you get the idea. The last thing to do is to drill the holes on the shield to match the holes on the arms. Measure in 3/16” from each leg of the triangle ends near the point and draw parallel lines to each leg. Where they intersect is where you need to drill another 9/64” hole. Be sure to get the holes on each side as close as possible dimension wise or else the shield will sit crooked. Once you’re done drilling, file down the point of the triangles to allow the shield to pivot on the arms. That’s it! Using the 6-32 screws and nuts, Test fit the pieces and make adjustments as needed. The shield should sit fairly level and straight if your bends were clean and your holes were in the right place. Hold down the arms on a level surface and make sure you can flip the shield up and down smoothly. The lip of the shield should point in the same direction as the long part of the arms when installed. This is what I call the down position and the one that forces the air out toward the cab. Flipping the shield toward you 90° will put the shield “up” and allow air to hit the windshield in the normal defrosting setting. Take the assembled parts out to the jeep and make sure things line up nicely. You may need to trim the arms a bit but mine fit fine once I allowed for the clinometer. If you’re satisfied, paint the parts and let dry. Reassemble them once dry (I’d put a washer between the arm and the shield to keep the new paint from sticking to itself) and lay them in place on the dash. Be sure that the shield’s back edge covers the vent entirely to maximize air flow toward you in the down position. To attach the arms to the pad, I used #8 sheet metal screws 3/8” long. Just use a marker to mark the dash through the arm mounting holes and go to town with a screwdriver. The sheet metal screws will pull themselves through the soft plastic of the dash without any pilot holes so don’t worry about that. Just be sure not to strip the plastic turning them in too far. That’s all there is to it. Just as a side note, you’ll need to make double of everything here to make two sets for both driver and passenger side vents.

Here’s the finished project installed in my jeep. Note the waviness to the shield lip. That’s from trying to bend this one in the vice. Didn’t work too well.

In my opinion, anyone who lives in a seasonal climate where you use the heater at least part of the year needs to do this mod. I’ve had mine in for a week now and already I’m wondering why I didn’t think of it sooner. The simplicity of the project makes it a great cheap mod and makes driving in the cold weather much nicer. I have noticed that the air tends to deflect outwards toward the doors more than straight out, which is ok since the door windows get a defroster effect and the heat still warms the steering wheel and my thighs. Haven’t got the pass side installed yet so I can’t comment on that, but I expect a similar effect. If your wife or girlfriend has complained about your heat in the past, do this mod ASAP! ;) Total cost for me was $0.00 because it was all scrap and loose nuts and bolts that I had accumulated from other projects. I even had the gray spray paint to match my interior. If I had to buy everything, it would still be less than $20 for a complete set. If you have to buy a big sheet, it would cost more, but you’d have enough metal to do several sets. I priced a piece of 16ga A36 sheet, 12”x12” at just under 7 bucks. I’m not suggesting you buy from there (12x12 is too small anyway unless you want lots of waste) or use that alloy (A36 is your basic structural steel) but you get an idea of the price. A 15x15 piece would be enough to do 3 sets of these so your price per set would be about 4 bucks in steel. Add three bucks for a can of paint and just pennies for the hardware to put it together. Not too bad for such a useful mod. It’s a great project for any of you HS guys in metal shop or anyone who wants to try their hand at some sheet metal fab. If anyone is interested in buying a set or two from me, I might be willing to do a few more. Just PM me and we can talk. Happy fabricating guys and girls! Any questions just let me know.

CanukYJ 12-06-2004 10:53 PM

The idea sounds great sentinal, but on my side the pics aren't showing. Anyone else having that problem?

sentinal02 12-06-2004 10:58 PM

There. Pics should be up and running now :thumbsup:

CanukYJ 12-06-2004 11:27 PM

Bingo, thanks sent :thumbsup:

drew2000 12-07-2004 05:05 AM

Very nice work, and excellent write up. :thumbsup:


JKNIPE2000 12-07-2004 06:44 AM

you should make up blueprints, patent it, and sell the prints to an aftermarket company for a nominal fee.

Jeepsohigh 12-07-2004 08:00 AM

wow....what a good idea.......I think I will make one before you get a patent....(LOL)

Synthisis 12-07-2004 08:24 AM

I was gona say get a patent on that thing. Have u considered making more and selling them?

Jeepsohigh 12-07-2004 08:32 AM

My wife will love she cant use the exuse that "it is too cold to take the jeep".....she will have to use somthing else....LOL

COJAM 12-07-2004 09:45 AM

I really wish I had that much time on my hands. How do you guys think this stuff up. Good work. Gonna put that together this weekend.

BackRoadJPin 12-07-2004 10:55 AM

Tag for later, and excellent write up 'Sent' once I am moved into my new house, this project will be next for sure -- last week solid been waking up to 16-19 degree fahrenheit temps and the alternating hands things is so true and pretty fun with a 5 speed.

BackRoadJPin 12-07-2004 10:57 AM

Thought I would just add an after thought to this as well.

to minimize rattling maybe add thin rubber covers on the edges making contact and if you are not willing to drill holes into your dash to mount this maybe some industrial strength velcro for quick removal the following spring.

ryanfritz 12-07-2004 11:13 AM


Originally Posted by Synthisis
I was gona say get a patent on that thing. Have u considered making more and selling them?

i'm moving froim hawaii to colorado, i'll take a set!

BackRoadJPin 12-07-2004 11:28 AM


Originally Posted by ryanfritz
i'm moving froim hawaii to colorado, i'll take a set!

:rofl: I bet you will ;)

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