EB338

I have heard more than a little talk about A/C and climate control problems with our cars and someone once told me the best solution for early cars was to convert the whole thing over to the late model parts. Is this truly the best course of action? Is the later system different? Is it truly automatic climate control like in the newer Caddi's and such where you set the temp and it does everything itself? Has anyone ever added rear A/C to an early car? How big a project is it?

SharkSkin

The early cars are the simplest and most reliable IMHO. The AC is either on or off, it does what you tell it. Cars from '80 on (IIRC) have the climate control with inside & out temp sensors. This is a more complex system, and I think you would have to replace the console unless you could drill your old one and find a way to mount the temp sensor. From what I can make out in the PET parts software, the main HVAC box is different and would need to be changed out. That's all the parts between the vents in the console and the blower, essentially.

Rear AC would be a huge PITA to add IMHO, since there are hard lines that can't be retrofitted without pulling the engine or cutting them and having an AC shop splice it back together. Then there is all the wiring, the rear AC controls that go in the lower section of the console....

IMHO it would be cheaper to just buy a shark that has climate control and rear AC already if that's what you want. It might even cost you less than modifying your early shark, especially if you would pay for most of the labor.

FWIW, I put a Griffiths compressor on my shark, 2 new hoses & one rebuilt hose, and the system is adequate for a black on black Calif. car. Around $1000, including what I paid the AC guy to do the final leak check, vac & charge. I did all other work myself.

EB338

My real interest came from being told the best solution was late model component upgrade so I figured if that had to be done why not get all the toys in the process. My car will be largely apart in the process of its rebuild anyhow so that is not a real concern. The Griffiths compressor is an upgrade from the original unit? Did you go with 134 or R12? Mine too is black on black so cooling performance is my primary concern and my main reason for considering the rear a/c upgrade. If the factory system of the early cars like mine can be brought up to par I don't see the point in converting. Any other A/C upgrades anyone would recommend other than the compressor?

IcemanG17

EB
The HVAC in newer 928's (MY83 & newer) is a semi full climate control, like dave mentioned it uses an outside (on alternator) and inside (on dash) temp sensor...both fail occasionally and cause odd problems. The temp sensor readings and your choice of temp-vent determines how the system reacts.... In general the achilles heel of our HVAC systems is the vacuum system, look at the post I just put up today! The vacuum actuators leak and fail on almost every 928 out there, which causes all sorts of problems, typically constant heat & poor A/C.

Retrofitting a rear A/C unit would be very complicated and expensive! I don't think its worth it, just keep whatever system your MY has and make sure it works properly....the A/C system has enough capacity to cool a small car like the 928! Personally I would keep R12, R134 has gotten much more expensive and doesn't work as well as R12! A properly running R12 system should have air temps around 50 degrees colder than ambient!! I have seen air temps at my center vent as low as 20 degrees! That is with a broken Recir flap too, so 50 degree differential on fresh air!

EB338

Ice:

I was just reading your post actually, sounds like a huge headache I don't want if I can help it. Like I said, the ONLY reason was even considering it is that I was told the later parts were the cure for early model problems, but to me it sounds like quite the opposite.

SharkSkin

I went R134a when it was a LOT cheaper than R-12. Seems to be working fine, though not ice cold if I'm not moving and the front fan hasn't engaged yet. There are some details, like a different control switch for the 134, but essentially it works. The Griffiths kit is in the neighborhood of $700, with mounting bracket, hoses, compressor, clutch, and dryer. The coolant return hose is not included in the kit; rebuild yours for ~$60 or replace for $300+ new.

Randy V

Actually, due to the additional potential problems it presents, later model cars with the rear AC delete option are typically more desireable to those who know these beasts.

OrionKhan

I would agree with that. I just went through fixing a leak back there and replacing the rear expansion valve. A PITA for someone that rarely uses the rear AC. I would remove it if it wasn't another PITA.