Deinstalling original owner GM AC on a 69 L71

[Lawrence S.]

I am back to work on my 69 L71 that you guys helped me trouble shoot my ignition problem that then lead to the rebuild of the distributor, and installing a new wiring harness along with several other odds and ends. So this is an interesting car. It's a CA car with the original engine, smog, non-original M-22 and original rear end. Car came with a POP, original window sticker, original black CA tags, and original CA paper license plate from 69 along with other odds and ends. Oh and the other neat thing is that the tank sticker is still on the tank. Now the not so neat thing. The original owner's family in the Sacramento area owned a string of NAPA stores, and they still do today...as a side note. Based on my research of the car, the original owner decided it would be a good idea to put GM ac on an L-71. When I got the car the compressor was not on the car, none of the heat/ac defrost etc worked. You could hear a little vacuum action when I rotated the wheel but it was a mess to say lightly. I am now undertaking the removal of the ac system and re-installing the factory heater/defroster assembly and the blower motor assembly. The passenger compartment of the car, console, gauge cluster, radio is disassembled. The blower motor assembly is loose but not removed yet. This morning while laying in bed I thought....oh man what if the firewall was cut to install the ac system?? So my question is this, to install the ac system in a 69 would one remove the non ac components and install the ac system, or is there firewall cutting that would need to be done. I obviously want to get the ac equipment removed and just bolt up the non ac system with out firewall repair.

Thanks

Lawrence

[Paul D.]

Re: Deinstalling original owner GM AC on a 69 L71

Lawrence, If a FACTORY type AC was installed, I feel sure firewall modifications were necessary. Probably on flat surfaces and easily repaired. Have you gotten all the AC components off the firewall? If you have, I have my 71 non AC car torn down just a few miles from you that you could look at to compare the firewall to and take some pictures. I'm a fellow club member in the Carolinas Chapter but have been unable to attend events lately. Drop me an email if you are interested. Chip Drennan. pinebarkauto@aol.com.

[Duke W.]

Re: Deinstalling original owner GM AC on a 69 L71

A thorough review of the C-60 section in the '69 AIM should reveal whatever modifications were required at the plant to install the option.

[Lawrence S.]

Re: Deinstalling original owner GM AC on a 69 L71

I looked at the C60 section but will review again.

Thanks

[Lawrence S.]

Re: Deinstalling original owner GM AC on a 69 L71

After looking at section C60 in the AIM it does not look like any additional firewall penetrations were made. But man I can't get the box off the firewall. There seems to be on last fastener or something that I cannot locate. And of course with that 427 in the engine bay there is no room to do anything. Not fun

[Mark E.]

Re: Deinstalling original owner GM AC on a 69 L71

Lawrence,

What an interesting car and history.

It's not in front of me but I believe the '70 CSM (same book as the '69 Corvette) has a procedure for R/R of the evaporator and blower.

Do you also intend to cosmetically restore the engine compartment and drive train? If so, this and the AC work may be an excuse to pull the engine/transmission.

[Lawrence S.]

Re: Deinstalling original owner GM AC on a 69 L71

Mark,

Thanks for the tip. I will check out the CSM.
I don't intend on a cosmetic resto. The under hood look is acceptable.

[Mark E.]

Re: Deinstalling original owner GM AC on a 69 L71

See page 1A-32. It looks like the evaporator core box pulls "upward and out" without removing the engine. It does say the AIR system may need to be removed with some engines.

[Lawrence S.]

Re: Deinstalling original owner GM AC on a 69 L71

Thanks Mark.
Last night I got the heater/defroster assembly removed from under the dash. That was not easy but it was because I did not remove the hoses properly first. I don't have my car at my house with my lift so made for a tougher job.
I will review the CSM and start to remove the blower motor assembly. The firewall looks a little hacked up frankly. Repair may be in order? Will upload pics later.

[Paul D.]

Re: Deinstalling original owner GM AC on a 69 L71

Lawrence, I saw your post earlier as to no modifications were required to firewall for AC. I looked in my 71 AIM under the AC section, and while I saw no instructions on cutting the firewall, the opening appeared much larger and configured differently than on my non AC car. I wondered if bodies destined for AC received different firewalls or if modifications were made at another place on the assembly line. It is my understanding that AIMs are the collection of individual assembly instructions dispersed throughout the assembly line, so if the firewall was not modified at the station where the components were installed, there would be no instructions to modify. This is just a guess on my part. Any way, the offer still stands for you to come by and look at my non AC firewall. Nothing is on it now so you could take pictures and make a tracing of the opening if you like. Chip.

[Duke W.]

Re: Deinstalling original owner GM AC on a 69 L71

If the C3 body is constructed like the C2, the "firewall" is part of the floorpan panel, which is the largest panel on the car. If C60 requires a different part than base there should be a note in the C60 section for that part substitution. Also refer to the body sheet that shows the floorpan to see if there is any note about a different part for C60.

Duke