A/C wasn't working, then worked again??

[LIBRILZ]

I went on a hour and a half drive yesterday and before I left town I got gas and my A/C was working fine, then I get in the car and hit the highway when bam, I feel the car producing nothing but hot air

so of course in complete and utter denial of reality I try turning it back off/on numerous times to no avail, even turned the car off and then turned it back on, but nope..looks like I was going to be making this little trip in the heat

Well about 6-7 hours later it was nightime and I got in the car and lo and behold, the A/C was working again! Why now? It continued to work for the rest of the night..I haven't started the car today to see if the problem will replicate again but it was working again at night..what gives?

[macgiver]

mac,sounds like it's on the "cusp" of being low on freon,the low press. cutout on the verge of shutdown at "just the right amb. temp"- usually, maybe because of a new leak , hopefully you TOPOFF and find it was simply LOW - that happens in time to most cars.And possibly lasts this entire season or more - don't keep messin' with trying on/off/on/off/etc. Just go (somewhere , you?) and "UP' the freon charge! They sell the small can,size of 12oz beer,with the R134 hose.NOT recommended to get the humongous , w/sealer ,oil, and bullsH%$TT -size of french-bread!You simply need to see if ADDITIONAL PURE FREON is ALL it NEEDS.

[LIBRILZ]

Hmm..ok, I hope so..even when it wasn't working, when I tried to turn it on the get it working the car's RPMs would increase like it was kicking the compressor on, but yeah, nothing but hot air

Maybe it being a cooler temp outside at nightime it made it such that even with "low" freon it still works

[macgiver]

mac, yeah that is one of the things, now that your mentioned, if the clutch is in fact engaging? - AND THEN you get no cold or still intermittant AFTER the "small can" charge, even the "Jerk of all trades" that I am , I go to a professional , got a buddy , all around expert mechanic with shop and honest with A/C work too -is invaluable! If this is on the 90's zx ,likely a leak ,slowly worsened - so be prepared for like a hose, o-ring and hopefully NOT Condensor or COMPRESSOR SHAFT SEAL!! And I'm gonna guess that the rpm's increase is a "nominal boost" no matter if ECM senses a larger rpm increase by A/C IS needed, i.e. your gonna get that surge because ECM knows A/C enabled and gives it a "kick" regardless , THEN IAC further regulates idle.
Plan B is - there maybe , for whatever reason, U/V "Leak detection tracer" ALREADY in your system,those blacklight flashlights are common now , get one that "projects" well into areas where A/C plumbing goes - SEE any TRACER? Put can pure freon,like I said above - does it work? does it last?
If not NOW put a small can ,freon ONLY that DOES HAVE UV LEAK fluid . Now if it IS leaking out you may be able to see EXACTLY WHERE , yourself , NOT PAYING the $$150 AC diagnostic for that knowledge !

[Sstupid]

I replaced the compressor and dryer on my last M45. It is doable, but I have all the tools like the vac pump, gauge set, and recovery machine. I realize most people don't have that stuff, but it leaks out on its own you don't need the recovery machine. I love how everyone gets so up in arms about venting R134 to the atmosphere but they're okay with driving around with a leak for years. I'd rather people vent and fix the leak than drive around for years with the leak.

Anyway, I have a lot of experience with A/C, so if you tackle it yourself and need advice, I have it to give.

[macgiver]

mac, that's not SOstupid , thank you

[LIBRILZ]

Thanks for the replies, as of today It is still working fine, so I have no idea what happened or changed, I think it could be colder but by no means is it doing bad..today was mid 90s and I was very comfortable