Vintage Air Install in 1967 Corvette

This is what Vintage Air calls a “Sure Fit” kit and it sure will fit… if you modify enough stuff.  In my opinion, even with the difficulties encountered during the install, it is still the best kit out there for use in the mid-year Corvette.

Getting Started
The instructions say to remove the original heater and duct work which is best accomplished by removing the instrument panel and the glove box.  Removing the instrument panel is not REQUIRED but it does make the installation job easier.  They also say to install the replacement defrost duct before installing the evaporator.  In my case, the evaporator was in and out several times which succeeded in tearing the flexible hose that goes up to the defrost duct so my recommendation would be to install the defrost duct AFTER the evaporator is installed.  See note later ... this won't work!

Evaporator Installation
The installation of the unit behind the glove box is TIGHT to say the least.  The unit hangs from one of the lower glove box mounting screws and a single hole through the firewall that originally held one of the anchors for the firewall insulation.  In my case, the insulation had to be removed from the firewall behind the evaporator to have enough space to install the unit.  I tried to install the unit for a couple of hours and finally decided that the evaporator was not the right one for this car.  I had posted some questions to the Corvette Forum and one of the guys referred me to an article that "Corvette Fever" did on installing Vintage Air in a mid year.  They had a LOT of VERY helpful pictures, one of which (left picture) showed the evaporator mounted in place.  That helped me realize that the unit was NOT supposed to be level once installed and from there, I was able to get it up into place and mounted. (right picture)

Microswitch Hits Firewall
I mentioned I had the evaporator in and out several times.  One of the major difficulties was that the AC-Heat microswitch lever ran into the "kick-in" in the firewall that houses the wiper motor.  There was NO way the unit was going in without the switch lever being bent.  I finally pulled the evaporator back out and modified the switch lever so it would clear the firewall and still work.  In addition, the attachment of the control cables needed some careful "tweaking" to make sure the cables correctly activated their respective controls.

Console Trim Won't Fit

One of the most puzzling issues I ran into involved the console trim.  There was simply no way it was going to fit back in the car.  It ran very solidly into the passenger side heater duct.  I called Vintage Air and they said they always recommend installing the evaporator with the trim in place.  That brings up a MAJOR issue in my mind because there is a screw in the trim that would end up under the evaporator.  In addition, obviously the heater duct would end up being significantly bent up to sit on top of that trim.  Since transmission removal (as an example) requires the removal of that trim to remove the shifter, there would be NO way to remove the transmission with the trim in place.  VA suggested they would expect someone to remove the evaporator to remove the trim.  This was totally unacceptable to me.

One of the guys on the forum said that he cut the back off his trim to get it in place.  I really didn't like the idea of cutting a $500+ piece of trim so I started looking at alternatives.  After much thought and measurement, I used an Exacto knife and trimmed away the offending duct just enough to get the trim back in.  I decided to do this in place which didn't result in the prettiest cut but I wanted to make sure I trimmed in the right place and I really didn't want to remove the evaporator again... although by this time, I was pretty good at it.  I would STRONGLY suggest that if anyone is having a unit installed, they tell the installer to at least remove the back screw in the trim.  Then you MIGHT be able to pull the trim out if necessary but you surely won't get it back in without modifying the heater duct.

Here's a picture of the trim installed after cutting the duct.  I did leave the trim screw under the duct out (for obvious reasons) so the trim can be removed if need be.  Again I will say that I think Vintage Air should STRONGLY suggest leaving this rear screw out on this side.  If someone has an installer put the unit in and that screw is left in place, there is NO WAY to remove the trim without removing the evaporator box.  That means you can't even replace the boot around the shifter or the carpet without dropping the AC!  That just doesn't make sense to me.

Defroster Duct Installation
I had originally installed the defrost duct as the instruction manual said, before installing the evaporator.  When I installed the evaporator, the hose, which is pre-attached to the duct got torn so I removed the duct, assuming I could install it after the evaporator... WRONG!  It wont go.  So, I dropped the evaporator again (I'm getting good at that now), installed the duct WITHOUT the hose and then reinstalled the evaporator, hopefully for the last time.  Then I installed the hose on the duct and secured it on both sides with a small machine screw.  In the picture you can see the first fitting of the hose from the evaporator to the duct.  The hose needed to be trimmed slightly but after that, it fit tight but fine.

Wiring Harness, Dash Controls & Passenger Side Air Outlet
The wiring harness was installed next.  The instructions are not real clear so you have to read the schematic to figure out where everything hooks up but it's not too bad.  There is one wire from the fan switch on the dash that goes to one of the microswitches.  It has a small connector on one end and a larger one on the other with a splitter.  The end with the splitter goes to the dash switch...  Next I installed the passenger side air outlet.  Other than the holes in the blower housing being in the wrong place to mount the duct, it went pretty well.  The hose needs to be forced through the space between the blower and the firewall to get it in but it went alright.  That hose was attached to the air outlet and retained with a small machine screw as well.  Then I discovered the air outlet covers the courtesy light.  I moved the light to the brace, left of the air outlet to complete that part of the job.

Vintage Air uses the factory heat controls to activate the heat and AC functions of this unit and unlike some of the competing units, there is no modification of the controls or the dash mounting holes required.  After getting the evaporator and trim issues resolved, I refitted the controls to the console.  Incidentally, I took this opportunity to lubricate all of the control cables with Teflon loaded silicone oil.  Be very careful of the passenger side outside air (vent) control cable attachment at the vent when installing the evaporator.  It is TIGHT against it and it can be easily broken.  I know this for a FACT!  I had to fabricate an aluminum bracket for the cable after the plastic one snapped off.

Console Side Panels Prepared
The right and left console trim pieces were next.  The passenger side one (top of left picture) would NOT fit between the console trim bracket and the vertical side of the console so I finally decided to notch the corner of the trim and after that, it fit very nicely.  After drilling the necessary holes for mounting and other items, the panels were painted to match the interior and they were ready to install.  The hose that connects to this panel is VERY short as you can see in the picture on the right but it does connect and it does work.  I run a compressor indicator LED on all of my AC systems and one of the holes in the driver's side panel is for that.  Another of the holes is for the clock switch.  Years ago, I rebuilt the clock and installed a circuit that takes all the load off the contact points inside so I also installed an on/off switch so I can leave the clock off if I like.  I typically turn it on only when the car is in a show.  The rear hole in the driver's panel is for the emergency flasher that is used in the '67.

Glove Box Modifications
Vintage Air doesn't address the issue of the glove box because it WILL go back in, in its stock form but at the expense of the right side air duct.  I put the box back in place and if bolted in, it would crush the hose to about 50% of it's original size.  In addition, the hose would be forced up against the windshield wiper arm.  I did some research and found that Classic Auto Air has a short glove box liner in their kit that is designed specifically to address this issue so I gave them a call.  They were happy to sell me a replacement liner for my installation.  The old box is about 6 inches deep and the new one is about 4 but I think that's much better than giving up the air flow or damaging the hose or wipers.  You can see the difference in the picture on the left.  With the new glove box liner, I was able to install the passenger side console vent and finish up that side.  Looks pretty good, huh?

Compressor Hits Inner Fender
Vintage Air uses compressor brackets from Alan Grove, part no. 118R.  The brackets are very nicely made and accommodate cylinder heads with both 3/8 and 7/16 holes.  Mine had one 7/16 hole so I had to drill out one hole in the bracket for the larger bolt.  Then I tried to mount the compressor.  No chance!  It ran HARD into the right inner fender.  I know the inner fender had been replaced at one time in the life of this car but it had never been a problem before.  Well, it is now!  A call to Vintage Air disclosed I DID have the wrong compressor (mine is supposed to have the suction and discharge ports on the rear of the back head) but the dimensions of the compressor will be the same so no joy, it won't fit! 

While a complete new inner fender is available ($345), I decided it was MUCH better to modify this one.  After all, I have known it had the wrong inner fender for years and it didn't seem to make any difference in my enjoyment of the car.  In fact, I know the front end of this car has been badly damaged in the past as evidenced by the fact that the steering column had been collapsed and very poorly repaired before I got the car.  Further evidence is that the hood has the support on the driver's side but there was no provision for the hood support on the driver's side and there is one on the passenger side inner fender indicating the inner fenders must be from a 63-65 Vette.  Many years ago, I fabricated a mount for the hood support on the driver's side inner fender. 

I first tried to cut a relief in the fender that I would have built a backing for but the rotation of the compressor on the brackets to tighten the belt still made it hit the fender.  With that, I got some dimensions from one of the guys on the Corvette Forum and then went to Corvettes of  Houston and took some pictures of the inner fender on a small-block '67 in their showroom.  It looked like my inner fender needed to move out about 2 inches so I went to work with the saber saw and made two vertical cuts in the inner fender.  I replaced the part I had cut out earlier and using fiberglass mat, I reformed the contours of the inner fender to clear the compressor.

I actually ended up glassing back the first section I had cut out and rejoined the first vertical cut on the rear of the fender.  The final fix was a "V" cut on either side of the splash shield.  Then I swung that section in about two inches and molded in the cut sections with fiberglass mat and resin.  There were two unused mounting ears on the compressor that were pointing toward the inner fender.  I removed them with a hacksaw and cleaned up the cuts with a file.  After that, with a 59 inch belt tight on the compressor, the compressor clears the fender with about one inch between the compressor and the inner fender.  To get the 59 inch belt on, you have to remove the adjuster bolt and swing the compressor toward the valve cover.  Then, with the belt in the groove, the adjuster bolt fits perfectly back in the slot.  I used a Gates "XL" belt from O'Reilly's and according to the Gates website, "...tensile cords within the XL belt contract slightly as the belt warms to its normal operating temperature.  This feature reduces maintenance because once they are properly installed, Gates XL belts rarely need to be retensioned."

Speaking of clearances, the belt JUST misses the lower radiator hose where it connects to the water pump.  I put an extra stainless clamp around the hose just in case the belt vibrates a bit.  It looks closer than it really is.  There is about 1/8 inch between the belt when it's tight and the hose.  Another close place is at the top stud for the shock absorber.  I'll cut off the shock stud a bit and slot the remaining shaft for a screwdriver in case the shock ever needs to be removed.

Electrical Wiring

The Vintage Air wiring harness is fed by two main wires; a red wire that includes a 30 amp breaker and a purple wire that is supposed to go to a line that is hot only with the key on.  The purple wire only energizes the power relay so it doesn't have to handle any appreciable current at all.  I connected that wire to the "heater" fuse in the fuse panel.  The red wire is the main wire that powers the blower and the compressor clutch.  Vintage Air says that wire is to go directly to the battery or the battery terminal on the starter solenoid.   That presents an interesting circumstance.  The '63-67 Corvette ammeter is actually a volt meter that is connected essentially from the alternator to the starter solenoid.  That means it is using the wire between the alternator and the starter as a shunt and measures the voltage drop across it.  The easiest way to explain this is if the starter solenoid end of the shunt wire is negative with respect to the alternator end, the ammeter will read positive and visa versa.  Hooking up the red wire to the starter solenoid means the ammeter will NOT read the load from the blower motor with the engine (alternator) off since it will not create a voltage drop across the shunt.  That alone is not a significant problem but if the engine (alternator) is running, now the current that is going to the blower motor from the alternator WILL show on the ammeter as a charge meaning that if the battery is fully charged, the ammeter will be still be showing a charge, equivalent to the current going to the blower motor.  In other words, when running the blower motor, it will appear that the battery is ALWAYS taking current from the alternator.  Not good.

I decided to fix that issue and in the process, address another known problem area in the mid-year Corvettes.  ALL the power for the inside of the car comes through an infamous "RED WIRE" that goes through the firewall connector.  It is not uncommon to have that connector go bad from the current draw.  Since I just replaced the engine harness, I knew the connector was clean.  In addition, when I put it together, I used dielectric grease on all the connections in the connector to help it stay clean.  I also ran another 10 ga wire directly from the alternator to a 50 amp breaker located right next to the voltage regulator.  From that breaker, I then ran a 10 ga wire directly through the firewall to the "hot" side of the breaker for the headlamp motors.  That effectively puts a 50 amp supply in parallel with the infamous red wire and the firewall connector.  The red wire from the Vintage Air was then connected to hot side of the headlamp motor breaker, through the supplied 30 amp breaker, mounted on the left kick panel, next to the headlamp breaker.  That should dramatically lower the chance of failure of the firewall connection as well as make the ammeter read correctly.

Firewall Cover and Hoses
Vintage Air provides a nice cover that goes on the engine side of the firewall.  In fact, a casual glance would make you think it was the factory box.  There are four large hoses that come out of the cover as well as two small vacuum hoses and the compressor clutch wire.  Two of the large hoses (black) are the vapor return line from and the liquid line to the evaporator.  The other two large hoses are for the heater.  I used Gates silicone (green) hoses inside the box because they are lifetime hoses and shouldn't ever need to be replaced.  That's a good thing because getting the firewall cover on (or off!) with the four hoses through it is a bit of a chore and I don't want to ever have to do it again.  One of the heater hoses goes to the hot water control valve as does one of the vacuum lines.  The other heater hose goes to the water pump through a 5/8 to 3/4 adapter (right pic) so I changed from silicone to Gates red hose at the heater valve and the adapter.  Incidentally, there are special clamps that are supposed to be used with the silicone hose.  In the case of the heater hoses, it's Gates #32312.  They have an inner shield that prevents that clamp screw from digging into the hose.

As mentioned, there are two small vacuum hoses.  Vintage Air identifies them as "red and black" although in my case, I saw no colors on the hoses and certainly not on the ends that came through the box.  .  The red goes to the water valve and the black to manifold vacuum.  It's important to connect the correct hose to the water valve.  If you suck on the two hoses, one is blocked and one is open.  The blocked one goes to the intake manifold.  If you connect the wrong one to the intake, you will have a constant vacuum leak which might result in a rough idle that would be LOTS of fun to figure out.  Of course, the ZZ454 is supposed to have a "nasty" idle according to Chevrolet so I probably wouldn't have noticed it anyway but it's still good not to have the leak.

While testing the unit, I discovered the fan would not work all the time.  After some troubleshooting, I discovered one of the relays supplied by Vintage Air was defective.  It had a loose terminal and when wiggled, the blower would turn on and off.  A spare relay from stock fixed that problem.

After installing the steering column today, (11/7/09) it was time to check the fit of the driver's side AC duct.  I couldn't permanently install it because I have to install the power booster for the brakes yet but I can't do that until UPS delivers the valve covers from Zip.  The new covers have the recess in them to clear the power booster.  I suspected there would be a problem with the mounting of the duct since the instructions show the mounting for an earlier car.  The '67 is the first year for the collapsible steering column so the mounting under the dash is completely different.  As it turned out, I was able to quite nicely mount it by fabricating a "Z" bracket that mounts off of one of the large bolts that supports the break-away pieces of the column.  Too bad that Vintage Air doesn't at least mention this but it wasn't a big deal for me to make the bracket.

On Wednesday the 9th of December, I took the car to Firestone in Spring and had the front end aligned.  Since I hadn't charged the AC yet, I removed the compressor so he could get to the "A" frame bolts easier and hopefully, would not scar stuff up under the hood.  I had to remove the alternator once I got there so he could get to those bolts as well.  After that, I brought it home and reinstalled the compressor and TRIED to hook up the last of the hoses.   The discharge hose from the compressor was just a little too short.  I could have probably tied it to the liquid line but it would have put undue strain on the hose so I called Vintage Air and it typical fashion, they were quick to say they would send out a slightly longer hose tomorrow. 

On Friday the 11th the new hose showed up and in no time, I had it installed and started pumping the system down.  Vintage Air says if it's not 85º outside, you should run the engine to warm things up before evacuating the system.  I not only did that but I set up the shop heater to keep things warm while pumping it down.  I also used a heat gun on the dryer.  After pumping the system for an hour, I sealed it off and watched the vacuum and check for leaks.  It held fine for 15 minutes so then I purged the system with Freon 134 and pumped it for another 30 minutes.  That should ensure it is about as dry as I can possibly make it.  Vintage Air says the 134 system takes 1.8 lbs. (28.8 oz.) of refrigerant.  After charging, the air temperature out of the center ducts (closest to the evaporator) was 36º.  Not bad!  That's going to be NICE on a hot day.  I took it for a drive and the air temperature out of the duct ran between 36 and 42º.  Of course it's only 48 outside but the compressor LED I installed earlier shows the duty cycle of the compressor to be VERY short in these temperatures, just as it ought to be.  With that, we put the hood back on the car and other than the seats and door panels, it's done.  Well, maybe not DONE but it's ready to drive!

I'm very pleased with the Vintage Air kit for the Corvette.  It's a bit of work to install and I probably made it a bit harder by making sure everything fit just as it's supposed to but I think it will pay off in the future.  I can't say enough about Vintage Air as a company.  They build a NICE product and support it very well.  No doubt I would recommend them to anyone wanting to air condition a car that didn't come with factory air.  All in all, I love it!

Last Updated:
4/1/2011:  Added driver's side dash pictures