The A/C setup in my Z looks like it was "meant" to be there. There's a metal mount for some little black canister on the wheeelwell between the cooling radiator and the passenger footwell how-ya-doin'. I always thought it was a dealer installed option but it looks like things were put in the engine compartment for the purpose of mounting the A/C hardware.

My understanding is that optional factory installed A/C was only available on the 1974 260Z and later models.

Where is the on/off/temperature knob located? Is it under the dash next to the trip meter reset knob or mounted on the console next to your right leg?

It's next to the trip meter.

I'm pulling the stuff out of the car. There are two hoses running through the firewall into ??? in the passenger footwell. Will I have to seal up the places where those hoses mate with the rest of the heating system?

You won't have to seal up anything since those hoses run into the a/c evaporator. I'd like to see some pictures of the system but it sounds like you're removing it. The 'little black cannister' is the reciever/drier and what I think you refer to as the 'cooling radiator' is the condenser. If it is indeed a factory system, why don't you repair it? I had actually read somewhere where some factory systems did appear on some late 73's.

no factory A/C in 73 model 240's sold in the USA.

"black canister" could be part of the emissions (evap) system on a 73 model 240z.

as for the holes (since you say you are removing the a/c), if you don't seal them you will have massive air leaks in the heater system and air will not flow as the system was intended.

Sounded to me like he was talking about the high side and low side hoses that run through the firewall from the compressor and the rec/drier to the evaporator. The only thing that runs through them is freon.

I'll try to post some pictures of it and the rest of the system tomorrow. I'm removing it mainly because I want to eliminate the weight. I'm going to hang on to the stuff in case I want to put it back in and after one summer in Middle GA, it may go in quicker than I think.

The little canister I'm talking about is about the size of a Coke can and has a small round glass "window" on top of it. The how-ya-doin' in the footwell is on the right of the heater blower motor and looks to be at least two large pieces of plastic held together by a row of phillips head screws. Will this thing come out with the rest of the stuff or is it a part of the heating system?

you could be right. hard to tell exactly what he's refering to without pics for confirmation.

edit: cannister as described is the receiver/drier

You have just described a factory system, regardless of what Garth says. (No offense) The 'coke can' is the receiver/drier and the 'how-ya-doin' is the evaporator box. It will come out but you'll have to seal the opening where it sends the cold air into the heater box. I'll post a picture in a couple of minutes. BTW, and I know I've mentioned it here on this site before, I'm a EPA certified MVAC tech.

EDIT: After checking my research materials, if your evaporator box is in the passenger footwell then sombody did a really nice install because that is the later 810-Maxima-ZX system. The early cars had the evap box behind the heater control panel in the middle of the dash. Now I'd really like to see some pictures!

You have just described a factory system, regardless of what Garth says. (No offense) The 'coke can' is the receiver/drier and the 'how-ya-doin' is the evaporator box. It will come out but you'll have to seal the opening where it sends the cold air into the heater box. I'll post a picture in a couple of minutes. BTW, and I know I've mentioned it here on this site before, I'm a EPA certified MVAC tech.

Not trying to wizz on you Stephen, but WHERE have you heard of factory systems appearing in 73 240Z's. I've never heard of that before. I'm also interested in how his description describes a "factory" system and not an aftermarket (dealer installed) system?

as for the holes you're mentioning that would send cold air to the heater box, that is what I was refering to in my first post when I said they'd need to be sealed.

I thought the factory system had the evaporator directly behind the heater control panel in the center of the dash and on top of the tranny hump.

Also nobody's mentioned it yet but what kind of compressor are we talking about?

Garth I apologize. Everything I've ever read says no ac until the advent of the 260z but I had heard somewhere that a small number were put on late 73 toward the end of that model run. I'd never actually seen one but I thought his could possibly be one of the rumoured 73s with factor air. Further research tell me that it could be a clever aftermarket install using factory parts becuse his evaporator box in the wrong place for a factory S30 system from any year (74-78). On the other point, we just had different concepts of what holes he was talking about sealing.