Factory A/C

[lemarin]

I'm having my LM-1 to my mechanic's garage right now, to bring her engine back to it's original state. Now I do have a question about the air conditioning. Correct me if I'm wrong, but according to the POP, only the power steering was installed, and the radio from the factory. (3 and 3)

Here's my POP:



When I bought the car, the A/C was installed and working. Of course it was not an original compressor, as the whole engine part we're swap for chrome part. But except for the compressor, the rest of the A/C component look pretty original from my opinion, even if the POP doesn't make any mention about A/C. Does the dealer could have add this A/C after the car was bought ? Does a dealer installation look the same as factory installation ?

I notice that there's a little metal plate, screwed on the rear right side of the engine bay, just above the A/C hosing. Does this small plate is related with A/C ? If yes, was it installed from the factory, or could have been added by a dealer, during the A/C installation ?

On the following picture (not my car), this small plate has 3 screws, and is located slightly right of the hood hinges, just by the rubber sealant for the hood.



What do you guys think, about this A/C story ?

[Kelley W King]

I have always thought back then dealer units were under dash and did not look like factory units

[69pace]

Yes there were mounted under the dash. A non factory A/C vehicle would have the wrong firewall opening for the factory "briefcase" to mount unless they went to great pains to do so, and the standard under dash unit would take a second to install compared to spending hours altering the firewall IMHO

[lakeholme]

My 68 has working factory A/C, but A/C units are a complete mystery to me.  The factory installed A/C was called "Four Season" and the dealer installed option A/C was called GM Chevrolet A/C, which mounted under the dash. As 69pace mentions above, the firewall without factory A/C had different openings. Does your car have any of the following, which were done at the factory for A/C?  Heavy-duty cooling system, higher output alternator, increased load-rated front springs?  The picture below is from the Accessories brochure.

I did find the plate with three screws, which you mentioned.  The plate goes under the cowl vent, which makes it hard to remove.  I could not find any mention of it under C60 in the 68 AIM or Service Manual.  And I do not have a non A/C Camaro handy to compare.  But like 69pace I do not see why that would be done for under dash dealer installed A/C.

[lemarin]

I don'T have the under dash A/C vents. I do have the regular clim control, including the A/C, and the cold air flow through the regular vents, everything looks to be right from the factory.

here are some pictures of the small plate I'm talking about, and my A/C hardware:

[lemarin]

[Mark]

That's not a small plate under the hood weatherstip, it actually runs all the way under the cowl plate, and has a vacuum operated damper attached to it, that seals off the fresh air into the interior blower for MAX A/C.  There is a small filer plate that sits at the back edge of the damper that is part of the car structure to completely seal the area behind the damper all the way back to where the windshield meets the top of the cowl.  You won't find that triangular plate in a non A/C car even if someone replaced the firewall with the correct one for an A/C car.  Also non A/C cars have fresh air vents up under the cowl that are attached to the upper vents in the dash.  If someone converted your car, those vent openings and maybe their close off valves will still be up there in the very far outer corners of the dash.  Of course you would have to pull the glove box, or the dash pod out to be able to see if they are there or not.  Looks like a proper factory installation to me.

[lemarin]

It's also my opinion even of I don't know very well this a/c system like you Mark.....but why do the POP is lying about the A/C ?

[69pace]

it wouldn't be the first pop that wasn't complete or accurate

[Mark]

POPs are typed manually by humans based on marked up broadcast sheets with the engine transmission and axle info hand written on them, not many are 100% correct as far as the extraneous option info is concerned.  Engine transmission and VIN numbers were the important stuff. 

[crobjones2]

Your A/C unit looks exactly like mine - factory A/C
Thus I have to echo mark:
look on the passenger side front footwell, the plastic cover should have a cutout to accommodate the valve actuator

if you plan on rebuilding the A/C - may I suggest Classic Auto Air - they restored mine!

Also look across the core support, there will be a foam weatherstrip and if you can see into the fender along the support there will be a block-off plate with rubber gasket bolted to the core support

[z28z11]

Mark answered the question that has nagged me since I bought my Z11 - is it factory A/C, added by the dealer, or an individual ? I pulled the cowl vent panel on my convertible, and low and behold, presto !
The cowl block off plate is right there, perfect example of what Mark mentions in his text above.

As a double check, I took a pic of my known (dealer invoice) X77, which could never have enjoyed the C60 A/C option due to the solid lifter motor, and you can plainly see where Fisher stamped the location (blank) in the cowl, and why it's there (to block off the upper cowl vent opening). Hope these are clear enough, and thanks to Mark for the clue as to factory originality. Just added to my own personal opinion of a Z11 convertible with A/C - -

Regards,
Steve

[z28z11]

Turned the Z cowl pic 90 so you can see the detail a little clearer.

Regards,
Steve

[click]

My 69 LM1 had factory air but I had no pop. Mine has the cutoff diaphragm that folks are talking about. These are several views of my factory setup:

[lemarin]

Thank you very much everybody for your numerous replies. I don't have access to my car right now, it's stored for the winter, but as soon as I can, I'll have a look to compare with your pictures.