A/C cycling back and forth between cold to warm
 

Hey guys,

So its getting a little warmer here in VT and I'm just starting to use the A/C in my car. I bought it used back in February - 07 GT w/ 38k.

I've noticed that the A/C while it is cold at the lowest temp setting, i can feel it constantly cycling to very cold, and then slightly warm ever 20 seconds or so as I'm driving the car.

Not sure if this is an indication of something failing, but I don't know what to expect in terms of the performance of the A/C in this car. As a side note, temp was in the high 70s maybe 70% humidity today so not super super hot.

Thanks,
Derek

Search noob.

im pretty sure its the soldering connections of your temperature knob. If you have the radio on, and you hold the power and seek up button for a sec or so, itll display the a/c temp. for me it will be at 0 and then switch back to 13 even though its on the coldest setting. Theres a diy on here to fix it but unless you have some good skills to start pulling that system apart, Id just keep the display on the a/c temp and manually do it

You'll sweat with 70% humidity...

Sounds like you are just low on refrigerant. Add some 134 to the system and see if that helps. You feel the cold air when the compressor is running. It gets warm as the compressor cycles off. Grab a can from your favorite parts store and a fill gauge. Make sure the can is right side up (do not turn the can upside down). Turn on the A/C blower on high. Connect the can to the low side port (closest to the firewall). Let it suck as much as it wants and then shut off the valve. Check to make sure the compressor is running continuously and not cycling.(note this is not the proper way to do it, but it will suffice if you don't want to take it to the shop.) The compressor should remain running. This should fix your problem. If not you may have a bigger problem that may require a shop to fix for you.

Just tried that this morning and the display just lit everything up across the board, I didn't see any numbers for A/C temp, all the numbers were 8s.

i think u did it wrong.

take a pic of what it's showing.

that's probably the worst advise for A/C

dude, u don't just add R134a in without knowing what the system has in the first place. adding too much might blow the rubber hose up and damage the compressor.

if u don't know how to fix something, please don't give any "advise"

Kind of hard to see - really sunny out today but I think you'll get the idea:

http://www.flickr.com/photos/dbove/7...in/photostream

yeah There is also that function too. What you do is, turn your radio so its ON. Now, put your finger on the power button for like .5 seconds and then ADD your other finger to hit the seek up button on the right side of the console.
If you hit these both for about 1-2 seconds, it will display what we are trying to say.



Also, dont listen to the guy who said that you should add refrigerant. I literally just did that LAST weekend, and it messed up my a/c even more. You cannot trust the pressure gauge on the store bought diy jobs. Im 95% sure what me and NYC said is your problem.

Ok got it, thanks for that. I think it was the Scan button and not the Seek button. I checked it this morning, and the A/C temp was 0 the entire time, so it must be something else. Its not that big of a deal to be honest, but I'm just wondering if its indicating a bigger problem.

The car had been sitting for probably 10 months before i bought it, so the A/C i'll bet hasn't been used in 2 years.

This is the answer. Search through the DIY section for the fix.

Well if it really didnt move from 0 the whole time, I guess we can rule that out, even though that really seems like what it is. The only other thing I can think of is that theres a major malfunction with either your compressor or part of the system. Im not a professional with A/C by any means, but like we advised you NOT to do, you shouldnt add refrigerant. That may be how your car got this way in the first place. You'll probably have to take it to a dealer. Which is a great idea, because you'll have it done right, and wont end up having damages.

On a side note, you should make sure the "recycled air" setting is on. If your A/C is blowing out semi-cool air, it may slightly improve conditions in the cabin. It did for me.

Goodluck man,

Suggestions?
 

I've done the defrost/recirc/ignition reset. I've also done the radio power/seek up getting the correct 1 - 16 sequence. It does blow cold air. My deal is that the compressor cycles on and off every 5 or 6 seconds (I have an '04 and have personally owned it for 3 years). It has done this since I bought it and I figured it must be normal since it cools fine. Of course in the few seconds the compressor cycles off it slightly loses its cold but comes right back when it kicks on again.
Considering everything I did appears to check out ok, could this be a case of maybe needing just a bit of freon?

no, just no

wtf ppl, really adding more does not mean its better.

AC is a sealed system if u lose refridgrant, u have a problem and adding more will not solve it.

if u suspect problems, go get a set of gauges and start from there. don't randomly add shit to it.

I didn't say I was going to add freon. I was asking if it could need freon. Jeez, everytime I ask a question on this site I get sarcastic answers. I thought this would be a great place to get info but its just not worth it always getting these kind of responses.

It could be but you really won't know until you put a set of gauges on it like NYCGPS suggests.

if it could be?

hang on, let me try my crystal ball and see if its gonna tell me what's wrong with it ...

wait for it ...

wait ...

oh snap, its not showing anything!

point is, u don't randomly ask if its this or that, if u suspect a problem, especially ac system, only way to find out is thru a test. u think its low on refridgerant, how do u know that? a set of gauges.

tell me its not true.

u do it right the first time, or u do it twice.

what happen to common sense these days?

u don't like my responds? too bad, what i said is true, u feel offended cuz deep down inside u know I'm right and it made u feel dumb.

i hate to say i told u so.

Yeah. I'm crushed.
How about a civilized answer like, "That could possibly be one of the reasons. I would suggest letting someone with a/c know how take a look though to find out for sure". Or, "I really doubt that would be the reason from my understanding of the system".
In posting my questions, I always hope not only to collect info from those with experience in the area, but maybe to also run across someone who had the same problem and what their resolution was.
I know better than to mess with it myself. Especially a/c.
I was just trying to find out if my problem pointed to a specific cause so that I knew what I might be dealing with in the future.

What I forgot to mention was that if the symptoms were a cycling compressor then he should do that. I was in a hurry and was a simple oversight on my part. Thanks for not letting the OP blow up his system.

At any rate, if the compressor is cycling it only does this for two reasons. 1. Low on refrigerant. 2. System is too cold and shuts down briefly to keep from freezing. If it is for reason number 1 it will still need to be refilled to function properly.

However I will concede that just throwing in refrigerant is not always a good idea and is most commonly a hint of another problem, such as leak, most common. If one can not fix the leak due to lack of skill or lack of funds then adding refrigerant to compensate for the leak will not hurt the system. There may be a small amount of air that gets in and it may not cool as efficiently as it should but it will not harm it. Overfilling the system could possibly ruin a compressor and you could blow something on the high pressure side. In addition, most people have no clue what they are looking at even if they had a proper gauge set anyway. With that said the only logical course of action for the vast majority of people is to take it in to a certified A/C technician and have them diagnose and repair it.

It is amazing to me that it is completely acceptable on this forum to be a dick. (my point, very first response to this thread "search noob" and no one says anything. I omit one statement and it would seem necessary to call me out lol. Any way just want to guy to get his air fixed all this other BS is unnecessary.

Dude you can not win on this forum when it comes to being civilized. This is the only forum I have ever joined that it is completely acceptable from the mods down to be a prick to everyone. If the compressor is cycling, you are most likely low on refrigerant. Putting more in there does not "fix it", but your not going to hurt it either, as long as you don't over do it. A set of gauges are required to be sure, but if you don't know how to use them, what's the point. Just put enough in there so the compressor stops cycling and give nycgps a heart attack

there are also other causes, but lets not confuse the op further.

i would rather be a dick than letting some wrong advise flooding around the forum just because someone was in a hurry and omg i oversight.

i guess its just too hard to do a search on Google to learn how to use a set of r134a gauge?

if op couldn't do that, well, i don't know what else to say.

u think this forum is low? hah, OK,i came from the good old bbs days and been thru millions of forums i think this one is already one of the best out there. if u think telling ppl the truth is being a dick then yea, i am one.

Sorry Guys But Jackson is right. The 8s are know for having a weak system anyway. Google How to read a 134 g then check for leaks....If in doubt you are better off shooting to an a/c place.....Its not rotary!!

Hey way to go deamon reply to a thread thats been dead for 2 years.

Try looking at the date of the last reply before you jump in.