Lugnut
HalfDork
6/22/10 12:39 p.m.
I got my '91 with the AC removed. I don't mean to sound like Bob Costas, but not having AC has actually kept the car in the garage on hot days (like today, in fact, and there is a Miata Club meeting tonight). I'd like to re-fit factory AC, but I'd rather pull R134a-ready pieces. Can I just pick up a set of used parts, bolt in, recharge, and go?
Keith
SuperDork
6/22/10 1:29 p.m.
I believe so. You might even have an evaporator under the dash already, look for some capped pipes coming through the firewall between the fusebox and the intake manifold. AC was a dealer-installed option in some markets, and we once had one of the install kits. I don't think I have the instructions for it anymore though.
You'll want to make sure you get a second fan and the relay to trigger it. You should have the wiring already.
Lugnut
HalfDork
6/22/10 1:30 p.m.
Keith, I don't recall whether I have said this before, but you are my hero.
Ian F
Dork
6/22/10 1:42 p.m.
If you need a/c bits, one of our region members posted the parts he removed from his 60K mile '94 when he did an R conversion. I think he still has everything. E-mail me if interested.
Lugnut
HalfDork
6/22/10 1:43 p.m.
Thanks, Ian! I'll ask at our local club meeting tonight and if I don't get anywhere I'll shoot you an email tomorrow.
Woody
SuperDork
6/22/10 1:46 p.m.
I've got an extra A/C fan if you need one.
Lugnut
HalfDork
6/22/10 1:57 p.m.
This was a factory air A-pkg car. I guess I need to see what pieces have been taken off and go from there.
jrw1621
SuperDork
6/22/10 8:21 p.m.
Not to steal lugnut thunder but my '90 Miata base model came from the factory with no AC. That was great in the years that I autocrossed it but after 17 years of ownership I now think AC would be nice.
Keith, do you know where to source a dealer install AC kit for a 1.6L ?
Keith
SuperDork
6/23/10 10:26 a.m.
The dealer? Try Marshall at MedCenter Mazda, but wait until Monday when he's back from vacation. If anyone can get one, he can. I doubt you'll be able to get a 20-year-old R12 kit for a 1990, but I think the 1994-97 parts should work just fine if they're available. Lugnut, if your car once had AC, I suspect you still have most of the parts in the car such as the AC fan relay and the evaporator.
One thing I forgot to mention - you'll need a new knob for the HVAC fan control. The AC cars have a button in the middle. All NA Miatas already have the button mechanism built into the controls, you just can't access it with the non-AC knob.
Fun trick to play on your friends that don't have AC: pull the knob off the fan control (just use your fingers), press the center shaft (it'll pop back out, like a button) and reinsall the knob. This turns on a little blue AC light just below the knob which can really screw with someone's head, especially as there's no obvious way to turn it off.
jrw1621
SuperDork
6/23/10 10:43 a.m.
Thanks for the lead Keith.
I have had these instructions bookmarked for years but have not sourced a kit.
http://homepage.mac.com/akerman/misc/90ACINST.pdf
I reinstalled the AC in my 1990 a while back. I used a R134a compressor from a 1999 Miata. It is not plug-and-play but it fits with some 'adjustment' of the lines. I think I had to reuse one of the old lines off of my old compressor to make the fittings match.
Keith
SuperDork
6/23/10 11:59 a.m.
I think if you use a complete 1994-97 setup, you shouldn't have to adjust anything.
Lugnut
HalfDork
6/23/10 1:02 p.m.
Yeah I have the button with the AC in the middle. I'll snap a couple pictures when it's dry out to see what I'm missing.