Condensation is only on the low pressure side.

Sounds like you have way too much coolant in there. Your gauge may be bad.

At this point go have them check your pressure and set right. No need to pull the vacuum first.

 

Well I got the car back from the shop and they said it was a bit low so they put in 3/4 lb of freon in. Good news and bad news. Its blows really cold now, but it still randomly shuts off. They are saying that its the a/c controller that's messed up.

That was my conclusion also since it was so slow to respond to the input, but I messaged a few guys on eBay that fix the controllers and 2 that responded say that it is not a controller issue? What would you guys do next?

 

It could be the pressure switch cutting the system off. I would have thought they would have checked that. Was the car still at the shop when it shut off?

Unfortunatly you might be chasing a problem for a while until you figure it out.

I agree that it is probably not the controller.

 

I can only seem to find the ac pressure switches for the C4's. Can you direct me to the C5 one?

 

Bump, I called the guy that repairs the ac controllers and he agreed that it could be the ac pressure switch. I still cant find one. Can anyone get me a link or part number?

EDIT: Is this it? Switch/Sensor same thing? http://www.amazon.com/ACDelco-15-574.../dp/B0012PKT9Y

I called the dealership and they wanted $61 for it and said it located on the back of the compressor, is it going to be a pain to get to?

 

did you read any of luckys posts man?

you could call a dealer and they could get you a part number real quick(edit:there ya go)...you could also use a site VENDOR such as Gene at GMPARTSHOUSE who posts up every day to help.

You could also do a search as every one of your codes has been discussed in the last 2 weeks multiple times by myself and others.

There is a thread called 'AC 101' i recommend you read that...then check out 'reindexing ac actuators' ...THOSE TWO threads will link you to just about any AC issue and the exact fix if you're willing to use a screw driver and a ratchet

 

Cranky? I did so much searching its not even funny. :P

The dealer wouldn't give me a part number b/c they were saying I would go buy the part somewhere else.

And all those codes lead to so many different thread's that I went though and didnt find anything relevant.

Finally found the AC 101 thread, didn't find any mention of a part number for the pressure switch or were its located exactly. And reindexing the actuators would not help with the ac shutting off.

I was simply asking for those two things. If that irritates you or something then just ignore me and move on. If I see something stupid in a thread I dont waste my time being a smart ***, I either help or not...

 

i'm not cranky...just sayin

here's the CODES that you posted:

99-HVAC - Heater, Ventilation, Air Conditioning
H B0361 Left Actuator Feedback Short to GND
HC B0363 Left Actuator Feedback Open
H B0365 Right Actuator Feedback Short to GND
H B0367 Right Actuator Feedback Open
H B0441 Left Actuator Out of Range
H B0446 Right Actuator Out of Range

Did you ever get any gauges on it yourself that you're sure are working okay? By checking on another separate car or calibration?

What did the high and low say? @ 2000 RPM? What was the humidity?


Why are you thinking a pressure switch? Did any code point you that way or just a guess or just cause it turns off or what?

Did you check the vacuum canister down below the battery(from the back of the intake manifold down to the cansiter?) there's a little nylon vacuum tube that can crack and cause the same air to blow out of all vents basically. if this isn't an issue you have, dont' worry about it for now


why would the dealer know you're going to buy the part somewhere else? don't be so obvious if that's your plan and they should be able to look up a PN in 2 seconds...**** just call back and ask for another rep and you'll prolly get ur answer

edit:i just went back and reread this thread again...pewters post about 3 down on the first page has what you need man...you say that you want to DIY and learn but you don't want remove any interior panels...you were specifically told what gauges to get and to check high and low side...you probably didn't even ask the shop what the high side was and i still haven't seen it posted.

it's tough to help

 

A decent set of gauges and vac would have cost me over $200 min. Im still in school now and barley have enough to buy a cheap set and everythig I make is going for tuition. Sometime later I will buy the required tools once I have more money... but for now, I'm working with what I got. I took it to a shop and had them check the level and fill it to the proper amount. The a/c always blows cool now, but it will randomly shut off after running for a bit and blow hot. If I pull the fuse and reset it, it will work for a few more min then shut off again.

The controller would be also be slow to react to what I pressed. For example, if the ac was set on low, and I clicked up and set it to max, it wouldn't do anything. Then 5 seconds later if I hit up one more time it would instantly be blasting cold on the max setting. So I fingered it was the ac controller (I also had to re-solder to fix the ac lights going out issue too, so I thought the controller was going out). As recommended by a forum member I called David Ruberg from www.speedometerrepairguy.com (he also fixes controllers). He told me to check the ac pressure switch and to replace that first. Which is what step I'm at now...

And as for calling the dealer, its not like I said right off the bat that I was going to buy the part from someone else, I simply asked for the price and part number.

Now please forgive my ignorance, but as for the actuator, can can that possibly be causing the ac to turn off?

 

I don't believe that the actuator could cause the AC compressor itself to turn off and on like you're describing...

There was a guy posting a week or two ago who him and his son had been trying to figure out why the AC just would not blow cold. They had been through EVERYTHING and done it all the right way.

His issue ended up being that the minimum side of the factory high/low pressure settings was just not enough.

What I mean is @ 2000 RPM you want between 27-35 low and 150-330 high. this allows for variance in humidity...he may have been @ 30 and 200 and got nothing. I mean he went through EVERYTHING had actuators out and replaced..checked voltages everywhere..pulled entire dash/interior. evacuated AC system...it was a couple week thing if memory serves.

long story short, he upped the AC pressure to say 33 and 250 and instant ice cold air all the time.

Other weird causes could just be that the car thinks it's freezing cold outside or the engine temps are running high?

Is your outside temp on the little AC unit above like 45 degrees and is your coolant temps running below 250 on the DIC?

 

The outside temp is usually +5 degrees over or so (like today, it was 98F but it said 103), and coolant temps are right in the middle (220). I dont think the outside temp sensor is busted if that's what your asking.

Also pretty sure not relevant, but oil sensor is busted, its always at 80+ psi...

What makes you so strongly believe that the ac pressure switch is not the problem?

 

just the fact that it's not a very common issue on these cars and there would probably be a code for that specific issue..your codes would lead me to believe it's an issue with the actuators. i just think that the mechanic that you're talking to is telling you an issue that is common to ac systems in general and not C5's specifically...

you're temps seem fine and the oil pressure is not related.

Is all the air that comes out of the vents equal? I mean if you have it on defrost and feet...is there ZERO air coming out of the "upper face" vents? or is there some air coming out of all vents or...?

What were your high side pressures?

 

The guy I was talking to fixes speedos and ac controllers. After I told him the problems he said its a common issue with the C5's and seems pretty confidant, he could have just "fixed" my a/c controller, charged me, and told me too bad. But he recommended the pressure switch first and then to get back to him, but who knows... as of now you have more credibility than he does.

Ill check all the vents tommorow and get back to you then. As for the psi on the high side I'm not sure, I had a shop check for leaks and vac and recharge if needed. I guess I should have asked what the pressures were...

 

really you should not have to worry about asking and the shop should know what to do...it's just in your case cause you know the codes and the symptoms, I would want to know to be safe

how much is the pressure switch? I just know that usually the codes point you in the correct direction and I have had VERY similar issues to what you are experiencing due to a stripped gear in the actuator and another that needed reindexing.

Its somewhat of a daunting job to pull the dash off but if you really search or just ask...there are excellent writeups here on the forum with the exact steps that are to be taken.

You're getting into stuff that is a little more difficult than just doing a tune up or an oil change, yes. BUT, you're saving a lot more money also

edit: another thing, just so you know...the vacuum tube and the ac actuators are VERY VERY common issues and the reason for their failing is very easily explained if you want to know...

The vacuum tube if you've ever had your intake manifold off is the little TINY black one with the 90 degree elbow that's always a PITA to get back on when you have to change knock sensors or have the intake off for any reason.
the reason for failing is because the factory battery on C5's is known to have leaked in quite a few cases(leaked acid) this will eat through just about anything, unfortunately the battery sits directly above the actual PCM and the vacuum canister/cowl drain. your main concern is the pcm and wires obviously.
seeing as your issues are AC though and you might be experiencing the same amount of air coming out of each vent OR not being able to keep the vents FULLY on HEAD, HEAD/FEET, ETC...ONLY with zero air blowing out of one while it's on the other setting...

the vacuum canister is easy to see, take the battery out and the black surround piece. pop the front tire off(car on JACKSTANDS) there's an access panel...it's easier if you take the bottom two fender bolts out for access too.

I'm pretty sure it's the one that comes directly out of the bottom of the canister that runs up and to the back of the intake manifold. again, there is a write up buried in here with detailed pictures (title or info is to the affect of "air comes out of all vents")

Easiest way is just leave the line in there, disconnect it from both ends and replace with rubber fuel line..your done and it's way easier to put the intake back on immediately and if you ever have to have it off again.

The ac actuators are a little more complicated but again with the amount of years/miles/open close cycles on your actuators. I would not be surprised if they are a tooth or two too "far" and need reindexing or replacing. you could try the 01-04 head unit also but again, how much is the ac pressure switch?

 

The pressure switch/sensor is $40 from amazon. When I set the a/c to defrost it does blow a little bit of cold air threw the middle vent but that is not my top priority right now. I just need to get it to stop shutting off on me.

If I'm not mistaken, the pressure sensor is supposed to turn off the compressor if the a/c psi is to high right? That's what seems to be happening in my case, the compressor shuts off after a few min and it starts to blow warm air at that point. If the switch is faulty them maybe its getting wrong readings and making it shut off?

That still doesn't explain the "lag" from the controls though... that has to be something involving the controller right?

 

I would really take care of the codes first man. the "lag" and the blowing cold/warm i'll bet is related. there should be zero air coming out of the center vent when you are on defrost...there is a vacuum leak at that line. i don't know what causes the ac system to shut off, all i know is mine shut off all the time just sitting at a light and i know my switch was good and my AC levels were fine cause it works great after fixing the actuator/vacuum line and having the EXACT same codes as you. it's free to pull the dash off, just set aside a day and get a helping hand to actually take the dash itself out. you can reindex the actuators and plug in to see if its' fixed.
if not, new actuators or a new head unit are the only way you are going to get your AC blowign cold. period

edit: i woudn't think the pressure readings would be correct with a bad pressure switch but someone will have to double check me. again, it would be good to know what your high side pressure is so you can eliminate that...the guys should be able to tell you at the shop u paid for teh AC job even if they have to hook up a gauge real quick
also the harbor freight gauge set is only like 30 bucks

 

I was "sort of" in your same position a few years ago with my 1996 Vette.....called a mobile A/C guy for an estimate. He drove to my office, fixed the problem in an hour and a half (for the estimate) and it still works.