This little "fix the A/C switch" problem is ballooning on me very quickly! The A/C unit in my car is not factory... but it appears factory. Basically, it uses a evaporator, expansion valve and blower motors all assembled together using the factory cover panel as a housing for the evaporator. This allows a fairly large evaporator and because its as large as the space available under the dash will permit, its probably about as powerful as is possible. I had thought of replacing it or having a custom unit built.... but after playing around with this thing it actually seems pretty good. With the fans on high, there is LOTS of air coming out of the box. The problem is, when the unit is installed very little air comes out the top vents. This is because the A/C unit basically has no plenum between it and the vents. When it was originally built and installed, sheet aluminum, aluminum duct tape, pop rivets and foam insulation tape were all employed to create what was a pretty effective plenum. the problem is there was no provision to remove the unit without basically destroying the plenum. Then of coarse the A/C blower fan switch went bad and to replace it you have to remove the housing.... I had the guy who recovered my Dash (Joe Nitti in FL... NEVER use him!) look into fixing the switch. As in, I told him to fix it. Well, he didnt. But what he did do was really screw up the plenum assembly. So, now I am in the process of getting my interior restored and while the seats and center console are out.... I wanted to fix the A/C. So I got the unit out, removed the switch (trying to find one of those still) and I got to looking at how I could rebuild the plenum and hopefully get even better air routing to the vents. It because pretty clear that the only way properly rebuild the plenum would be to remove the dash. Gulp. Im not even sure how the dash is attached. I need to remove the entire top dash panel, the one with the vents in it. If its possible to not remove the portion of the dash where the guages are housed, that would be great. Otherwise, I will be removing the entire dash assembly. Any idea how the dash is attached and what the best removal procedure is? The A/C system in my car will hopefully be pretty effective when this is done, except that to service it requires disassebling the entire freaking dash! Terry
Hey Terry, we definitely should get together. This week is good for me after it's stops raining. I've got my dash apart and it's not too hard if you're willing to remove the steering wheel so that the gauge cluster can move with the dash. If you just need a little wiggle room then you can probably just loosen 3 screws on the main dash. I've got mine completely apart and my A/C system is a mess too. I'll e-mail you my number again and let's connect this time. - mike
Terry: I have photos of the progress on my car, I will send them to you tonight. Why do you need to remove the instrument panel? The removal of the black plastic shroud is not a big job.PM me if you like.
My car's A/C is not a factory setup, it just looks like one when installed. The black plastic shroud on my car has been modified. It is now bonded to the twin fan housings and the under trey is also bonded to it and sealed. Within this box is housed the evaporator. In effect, the shroud now makes up the bulk of the evaporator housing. IT sounds strange... but after testing the fans and seeing how much air is blowing through the evaporator and out the top I view it as a pretty successful piece of engineering. Now I just need to reconstruct the plenum between this evaporator/fan blower assembly and the top vents. To do a great job of that, I felt the dash needed to come out. The car is now at Flashback Motorworks here locally. They are going to tackle it. I am hoping to make a big Italian car show here in Atlanta this weekend and with all my work commitments I just done have the time to work on it, so its farmed out. I am hoping with a new switch and more effecient plenum the A/C will actually blow pretty hard. Still interested in seeing details on your solution! Mike: I left you a voice mail message. Terry
Terry: Here is the evaporator unit and the soft gasket to the dash. I think the drain hole are a little high and allow some water to remain in the tray. The new evaporator is installed. I have pictures of it at home, will post. It looks stock except the tubes are fewer and the fins farther apart to let more air flow. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Malcomb.... Awesome! Very nice, looks like some great engineering work. How well does the air blow out the top? How cold is it? Even more important.... who made this unit, can they make more, how long would it take, how much would it cost? It looks as if you may have additional fan units mounted in the top cover panel on the evaporator housing? Actually, I would lay a wager that if you took a mold of the factory cover panel and made some duplicates, and you did a mini-assembly line for the evaporator/fan units like yours, you could sell 20+ of them for $1500 each or so. Might even sell more than that. Daytona ownes like A/C! Terry
Terry: This is all stock, the only custom piece is the evaporator which is in the metal can, not visable in these photos but I will show it to you. Your unit should look just like this, which is why I wanted you to see it since you mentioned you may have something different. When it is all operational I will report on the success or lack thereof. The evaporator in this photo is stock, note that you cannot see through it which means that the air has a hard time getting through. I will now look to see where I put the photo of the new unit which I took several weeks ago... Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Not going this route. My unit is totally different. The cover panel has been modified to actually house the evaporator directly. Also, the evaporator is a good bit larger than the one Malcomb has pictured. the thing about my unit is that it has no metal housing like that at all. There evaporator is inside the cover panel and it fills up the panel. The fans blow through it with pretty good force. On top of the cover panel is nothing.... thus we are fabricating a sheet aluminum plenum to route the air to the top vents. This setup will hopefully allow less restricted air flow to the vents and thus higher volume. Then again.... who knows?!? I dont have the metal housing as pictured by malcomb, my unit was custom built 12-14 years ago and apparently worked pretty dang good until the A/C blower fan switch died. Terry
Terry" I got it, yours is a different approach to increasing the airflow by increasing the volume of the container. Does the shroud get cold ? The other two things I think would help are to increase airflow into the footwell and to increase airflow into the box by diverting the fresh air intake to the box so 'RAM" air could come in from the outside. Then the second two dash vents could be connected to[unblocked'really] the cold air box, thereby doubling the amount of airflow to the cockpit.Of course we dont know if the evaporator would cool that much air. I elected not to do these things- a little more ambitious than I am prepared to tackle. However, since yours is already modified...... Also, I cant imagine why the rotary switch is such a hard to find thing, thankfully mine works. Does your set up include the resistors shown in the photo? The resistors are what controls the speed, right? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Terry Make sure that you insulate the outside of your box and ducts so they don't condense water inside your dash. Best
When it was working, the outer cover did get cold but I never noticed any water condensing on the outside of it. It has the two drains coming out of the bottom allowing for the water to drain out. The upper connections to the dash vents are just sheet aluminum but do have the aluminum insulating duct tape wrapping it. Terry
Ok Terry and others interested, we have completed the modification of my A/C, see the previous pictures. In addition to the new evaporator we resealed all of the connections between the parts so the air now goes to the vents instead of under the dash. We tested the switch which measures temperature of the coils and decided to replace it, then we put it back together. On the road it puts out about 30% more cold air. The switch allows the temp at the coils to drop to about 29 degrees F and then cuts off the compressor untill coil temperature reaches about 40degrees F, then it cuts the compressor on. The combination of better airflow, colder coils and better sealing results in very good cold air delivery withou the coils freezing, which was a previous problem. While watching it work the obvious hit- they built the thing upside down, the fans blow air up, along with the condensate, to the dash vents. If it was inverted the airflow would be down to the under dash area where vents could blow the air onto your body instead of in your face. I want mine to look stock so didnt do this, but if that isnt important I think it would really work. Anyway, mine is very good now and I am happy. Thanks to Gary Bobileff for the good work.Also the new alternator keeps the lights, fans, and a/c alive even at low speeds, this is a no-brainer as far as I am concerned.See you on the road to NO.