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2005 Impala


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olddude
Novice

Apr 4, 2012, 7:07 AM

Post #1 of 16 (5228 views)
  post locked   2005 Impala  

Hello, new to the forum and I was wondering if anyone had the location of the low pressure switch on a 05' impala with the 3.4 engine. We just got this car for my wife to drive back and forth to work and the AC don't work. I haven't checked the pressures yet but in just looking at it I can see the compressor isn't kicking in and the radiator fan motors don't seem to be coming on either. After digging around I did find the hi and low pressure service valves but it was getting dark and I never could find anything else. I want to check it out this weekend if I can find out where they hid the expansion valve on this thing. Thanks for your input.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Apr 4, 2012, 7:41 AM

Post #2 of 16 (5217 views)
  post locked   Re: 2005 Impala  

It doesn't have one. This is an expansion valve system. It uses a 3 wire pressure sensor in the liquid line that reports back to the PCM and the PCM makes decisions from there. You need a scan tool to see what the PCM is seeing.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Apr 4, 2012, 7:43 AM

Post #3 of 16 (5214 views)
  post locked   Re: 2005 Impala  

LPCO switch: Follow the larger line from the compressor all the way to firewall and it's got to be there. Some are actually under the car and some if line goes out of sight you need to remove something to get at. Wish I could be more specific.

It may not (can't say car by car) have a high side port. First get a static pressure which should be roughly the same as the temperature in F. in the area. Don't even think of adding anything from some can that isn't pure refrigerant w nothing else in it. Use real gauges not the crap they sell.

Keep in mind the problem may not be a low charge at all! If unsure just what you are doing get professional help or you could damage more than you could ever save,

T



Tom Greenleaf
Ultimate Carjunky / Moderator
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Apr 4, 2012, 7:46 AM

Post #4 of 16 (5210 views)
  post locked   Re: 2005 Impala  

Understood Hammer but if no port how would one service A/C at all if it did need a hose or something?

T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Apr 4, 2012, 8:00 AM

Post #5 of 16 (5200 views)
  post locked   Re: 2005 Impala  

He didn't ask for a port. He asked for a switch.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Apr 4, 2012, 8:09 AM

Post #6 of 16 (5195 views)
  post locked   Re: 2005 Impala  

My fault sorry. Time for new glassesCrazy

Tom


olddude
Novice

Apr 4, 2012, 8:16 AM

Post #7 of 16 (5193 views)
  post locked   Re: 2005 Impala  


In Reply To
LPCO switch: Follow the larger line from the compressor all the way to firewall and it's got to be there. Some are actually under the car and some if line goes out of sight you need to remove something to get at. Wish I could be more specific.

It may not (can't say car by car) have a high side port. First get a static pressure which should be roughly the same as the temperature in F. in the area. Don't even think of adding anything from some can that isn't pure refrigerant w nothing else in it. Use real gauges not the crap they sell.

Keep in mind the problem may not be a low charge at all! If unsure just what you are doing get professional help or you could damage more than you could ever save,

T

Yeah I know about that.Wink I found the two service ports but could not find anything that looked like a normal switch with wires coming out of it. The inside hood area is so packed full of stuff it's hard to tell what is what. All I know at this point is there is no power to the ac clutch or fan motors so something is not sending a signal. I guess i'll have to get a scan tool and see what that tells me. Thanks



Tom Greenleaf
Ultimate Carjunky / Moderator
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Apr 4, 2012, 8:42 AM

Post #8 of 16 (5186 views)
  post locked   Re: 2005 Impala  

Got it. It should still shut down if just a static pressure isn't adequate and some of this style will stay off if there was a problem. Most common problem is still leaks and if so should shut down to save the system as if they run with a low charge the oil stops flowing which would kill a compressor running dry.

If not familiar I still say get help as the correct charge is so important and too much is a bad thing to a disaster on many,

T



olddude
Novice

Apr 5, 2012, 7:22 AM

Post #9 of 16 (5136 views)
  post locked   Re: 2005 Impala  


In Reply To
Got it. It should still shut down if just a static pressure isn't adequate and some of this style will stay off if there was a problem. Most common problem is still leaks and if so should shut down to save the system as if they run with a low charge the oil stops flowing which would kill a compressor running dry.

If not familiar I still say get help as the correct charge is so important and too much is a bad thing to a disaster on many,

T


Yeah that's what I was thinking and thought I could trick the system into thinking there was enough charge to start the compressor long enough to see if it is in fact low on freon or something else.

I've been servicing my own equipment for years and have pretty much all the equipment to service any AC problem that comes up. This car however is the newest one to date and I can already see that they plan on you bringing it back to the dealer if anything at all goes wrong. I learned my other cars and hopefully I can learn this one too, however the newer they get the harder they have become to work on because of all the computer controlled gismos packed under the hood.

In Reply To


Hammer Time
Ultimate Carjunky / Moderator
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Apr 5, 2012, 7:32 AM

Post #10 of 16 (5132 views)
  post locked   Re: 2005 Impala  


Quote
have pretty much all the equipment to service any AC problem that comes up.


If you had anywhere near the knowledge or equipment needed to do this you would have already taken a pressure reading and you would know if you have sufficient pressure to start the compressor. You don't find refrigerant levels by tricking a sensor and if you try that with this system, you may be buying a computer. If you don't have professional gauges, ship it to a professional.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Apr 5, 2012, 8:01 AM

Post #11 of 16 (5123 views)
  post locked   Re: 2005 Impala  

This isn't like a regular CCOT type system so no tricking as is/was done for complete charging that doesn't apply to this. If plain static pressure is pretty much below ambient temp in F. then when it was working it was WAY too low and shut down and should.

Static pressure isn't the answer but tells that there isn't a bullet hole leak anyway and a place to start. Doesn't mean it's properly charged at all and still may not be the issue at all.

Send this out before you wreck it by the thousands. You aren't saving a penny trying this yourself without all the equipment needed. Starting this up may take a tool or other procedure but would be best to find out why is quit, if a leak fixed not just filled and filling it should be from a well held vacuum to exact weight called for and doubt you can recover what might be left in it or do that. No guessing with this stuff or risk everything!

T



olddude
Novice

Apr 5, 2012, 8:04 AM

Post #12 of 16 (5120 views)
  post locked   Re: 2005 Impala  

Okay, I see this place is like a lot of the others I have been to when looking for information. Look! I don't know you or what your qualifications are and I'll take a guess and say you have no clue as to what mine are. If you read my first post I stated that it got dark before I had a chance to hook up anything. I plan on looking at it again this weekend and just wanted to get a heads up on where they hid certain things on this car is all.

I didn't want to get into a pizzing match with anyone over this and trust me on this I understand why some people don't like to give out certain information over the internet because of the dangers involved with some of this stuff. However....I don't have a team of lawyers sitting around waiting to sue you over something that could happen to me or my car if something bad happens.

But, having said all of that I landed on this site because when I goggled AC help forums this one came up along with ten thousand others. Right at the top of this page it says...."AC Auto Repair Help Forum" If that is a misprint, please by all means let me know and I'll move on to somewhere else.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Apr 5, 2012, 8:29 AM

Post #13 of 16 (5118 views)
  post locked   Re: 2005 Impala  

Hey - only two of several here responded both ASE certified -are you in MVAC (bet you don't know what that stands for) vs HVAC. Lots of different ways to get the same thing done and this one isn't just plain and requires equipment.

You still haven't posted so much as a static pressure as a beginning so that alone shows you are out of your league,

Thread locked. Go to one of the other 10,000 sites and blow your system up. We offer a money back guarantee here and since it was free that what you get,

T


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Apr 5, 2012, 9:01 AM

Post #14 of 16 (5109 views)
  post locked   Re: 2005 Impala  

Let me tell you one thing. I am in South Florida and have worked at shops that do nothing but A/C and there is never a reason to jump out a switch except to test the switch itself and even then a smart tech would be using a test light instead.

ALL A/C checks start with a pressure check and right then you know if there is enough pressure that the compressor should be kicking in or not so don't try to make believe you have any idea what you are doing because we can tell the difference in a heartbeat.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Apr 5, 2012, 9:07 AM

Post #15 of 16 (5106 views)
  post locked   Re: 2005 Impala  

Where's that fish you posted?


nickwarner
Veteran / Moderator
nickwarner profile image

Apr 5, 2012, 6:10 PM

Post #16 of 16 (5089 views)
  post locked   Re: 2005 Impala  


In Reply To
Okay, I see this place is like a lot of the others I have been to when looking for information. So every site full of people who know what they are talking about give you the same answer, and you think we are being dicks to you because we didn't give you the answer you wanted to hear. Open your nearest Webster's dictionary and look up insanity. We could care less about someone suing us for advice, teams of lawyers, etc. This site is free advice, not a paid service, and our legal culpability is about nil. The warnings you got from SEASONED AC PROFESSIONALS who know to the letter what they are doing are to protect your wallet. We didn't design your car. We didn't build your car. Think it sucks to pay a shop to fix this, try being the shop owner who has to drop $10,000 on new equipment because some engineer in Detriot saved $10 per car by changing the AC system to the mess you have in your driveway. The engineer doesn't care, he gets a fat bonus. We get huge overhead and customers who act like its our fault their car repair bill is more expensive than the AC job they got in 1985! You were told to let this thing be left to the pros so you don't turn a $500 job into a $2000 job. But ignore the advice at your own peril, as it will cost us exactly what our advice cost you.






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