Garrettfranks

AC blows, but blows hot. I know nothing about Air Conditioners, filled it with freon, still doesn't work...compressor doesn't kick on, but it wont if its not filled? if you 'jump off' the compressor it will turn on. thats because it knows that its low, so it won't turn on. guy at autozone says i have a leak, how would i go about finding a leak?

hoov100

Take it to an A/C shop and tell them whats wrong and ask them to fix it.

The guys at autozone sell parts, they don't use them, design them or install them. So pretty much they are useless for anything but getting parts and checking out...

NismoPick

You filled it with R12 freon? Yourself? You have R12 freon?

x2 on the AutoZone guys... they don't even have the hoses to check R12 systems anymore.

reddzx

Its blowing hot because you have a major vacuum line leak. The climate control reverts to default (hot air from the defrost) when it has no vacuum pressure.

Garrettfranks

isn't freon freon...? would the wrong type make it blow not cold?

EZee

The system was built to operate on R12 which is no longer produced (some shops may still have some). If you bought a can off the shelf, it's R134 which is not compatible with R12. I don't no what kind of damage mixing the two will cause, but I know that you're not supposed to mix them. R134 is also designed to operate at higher pressures that the R12. The system can be converted, but it requires repalcing some seals and flushing (evacuating) out all the old refrigerant. Your best bet is to take it to a shop. Make sure you tell them you dumped 134 in there so that they do a good flush. Then either have them convert it or find some R12 for you.

Garrettfranks

thanks so much man

NismoPick

^^^ So does that mean you added R134a or R12 to your system?

And did you see this post?

hoov100

Unless someone added the 134 fittings to his system, I doubt he got anything in it.

Tarajr

how do you find the vacuum hose with the leak? My AC works fine until there is more than a 10degree diff between the temp I set it to and the Ambient temp, at which point, the cold air reverts to the defrost vent. if I reduce the set temp by under 10degrees, it goes back to blowing out of the proper vents. I cant figure out how to locate the vacuum hose that is damaged.

Tarajr

this seems like a common issue and I found a great posting on the subject. Doesn't tell you where to look but explains the problem. I hope this helps others...

How do you repair a 1986 Nissan 300ZX that blows hot air even on the AC setting

zdadgeezer

This may be a bit off topic. If so I apologize but since there may have been a mixing of disparate gases(a definite bad thing) like R12 and R134a I have included this info.
There is about a 50/50 split on how many A/C techs know that you are not supposed to vent or mix gases as well so read up and don't get hurt.
I have been investigating A/C updating.There are retrofit kits for R12 to R134a. It is also recommended that if the A/C system is working to just recover the old refrigerant and retrofit no major parts involved just adaptors on the valves and re-labeling of the compressor.
There is also an alternative called R12a an HC based product. I have included a link it is supposedly a drop in replacement for R12 without any need for replacing parts etc... also lowers the operating pressure and temperatures of the A/C system and is compatible with most oils. The only thing would be it is required by law to recover all refrigerants(can't just open and vent) there are kits for this as well. If I decide to go this route as opposed to retrofit to 134a I will post results.Automotive Air Conditioning
It appears to be recent in introduction so it may not be well known. I will continue looking into it and post what I find good or bad.

R12 is still available although pricey. It is not manufactured in the US anymore. So I would at the very least consider the 134a retrofit(not as bad as it sounds) if the R12a doesn't pan out.
Just a reminder: NEVER mix gases. A drop in substitute does not mean it can be mixed with(12 and 12a eg.) different beasts altogether.
Recover the old- you or a professional if you do not happen to be an AC certified tech or inclined to do so-Replace with currently available technologies you will need to study and make the best decision for you. Good Luck and stay safe, Hope the info helps someone.