KHE Posted March 31, 2005 Report Share Posted March 31, 2005 I am attempting to help you - but I need some information as it can be difficult to diagnose a system via the internet - see my post above. It sounds like someone has butchered up the system as the stock system only has ONE orifice tube. That is all that is required - if someone has added a second tube, that is an unnecessary restriction in the system..... Did you have the system leak tested? Have you checked the onboard diagnogstic system for trouble codes? Was the system vacuumed down prior to adding the R-134a? Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
JoeM Posted March 31, 2005 Report Share Posted March 31, 2005 And you cleared the code from the computer that disables the compressor through the onboard diagnostics or by disconnecting the battery for 30 seconds???? And you recharged the system without the compressor running how??? Link to comment Share on other sites More sharing options...
Scotty Posted March 31, 2005 Report Share Posted March 31, 2005 THIS PAGE IS INTENTIONALLY BLANK..... (cause I messed up) Link to comment Share on other sites More sharing options...
Scotty Posted March 31, 2005 Report Share Posted March 31, 2005 If I am not mistaken the system is kicked on by high side and low side sensors that read pressure differential or peaks I am not sure. Look for loose electrical connections along the tubing. It may have a bad sensor. Reply to Kevin's post so he can help you, I will read the manual and see what I can learn here. Link to comment Share on other sites More sharing options...
clusco Posted March 31, 2005 Author Report Share Posted March 31, 2005 I just talked to a mechanic that previously worked for Cadillac and he told me that my system won't actually kick the compressor on until I physically reset the climate control in the display so that it knows that it has the desired amount of freon. Does this sound right to anyone? Link to comment Share on other sites More sharing options...
Ranger Posted March 31, 2005 Report Share Posted March 31, 2005 Well, if you have a low refrigerant DTC and the compressor was disabled, yes, you have to clear the code before it will enable again if that is what you are asking. Link to comment Share on other sites More sharing options...
clusco Posted March 31, 2005 Author Report Share Posted March 31, 2005 Guys, I am sorry I wasn't answering your questions about the codes. I didn't realize that the post had more than 1 page. I thought my new posts simply weren't showing up.\ Anyway, the codes I pulled are: T063, T033, I033, I039, AND A012. Hope this can help Link to comment Share on other sites More sharing options...
clusco Posted March 31, 2005 Author Report Share Posted March 31, 2005 Do you mean the dealer changed the orifice tube again? There is only one orifice tube in the system. Was the system evacuated with a vacuum pump before the R-134a was added? Did you extract the codes from the onboard diagnostics like I suggested in an earlier post? Ok, here's the deal. Please bare with me as there were a few different situations. I brought the car to get the system evacuated and charged one day at a shop. At first they, like most I found, did not want to work on my northstar system. They did it because I told them they didn't have to accept responsibility if something went wrong. So the first time they charged it, they told me after they did it, the compressor was bad. I put on a new compressor and brought it back the next day. This time the charge took and it worked for about 3 days. On the 4th day it blew nothing but hot air. Thought I had a leak. Tried to administer the dye myself. Tried it before putting the freon in once and tried it after once, while tripping the compressor on. Either way, the dye would not take. The freon took fine but the dye just shot right back out from the can. So I brought it to the shop again to get them to check for a leak. They told me that they couldn't get the dye to take because they couldn't trip the compressor on this time, but they tried to trip the compressor from the drier's switch and not from the relay switch by the fuse box in the engine compartment, like I did. I showed him how to do it this way and when I showed him this, the 2nd orifice tube on the firewall (that someone installed before I bought the car) was vibrating violently like there was a lot of trash in it stopping it up. The guy said that it looked like this was my problem because the system was definitely full of freon. So I went and bought a new 2nd orifice canister and installed it. When I evacuated the freon this time to install the 2nd orifice, it took a very long time to empty so I know that there wasn't a leak because it took so long to empty (probably had 6 cans of freon in there). So I thought for sure that this time everything would work since the system wasn't clogged anymore. Now, it's important for me to tell you that I added the freon to the system myself without any vaccuum or anything. I just hooked the freon to the drier, tripped the compressor, put the A/C on high and 60 degrees and filled it up. I tried to put the relay back in and the compressor would not come on! So, I tried switching relays, thinking maybe this was the problem but the other relays worked the same. I did want to say one thing I noticed last time I added an extra can today. I noticed a little water bubbling and could feel air coming out on my hand near where the A/C line enters the firewall near the glove compartment. I thought the water was just cold condensation from the pipes. Some of the rubber there is flaking and you can feel air coming up right below where the A/C pipe enters the firewall. Where the air is coming from cannot be seen because it's actually underneath this rubber insulation. I thought this was just the vents' air coming back out but could that be leaking possibly? And also, if this is a leak (near where the heater core would be), wouldn't all of the freon have left the system in a day by now? Link to comment Share on other sites More sharing options...
Scotty Posted March 31, 2005 Report Share Posted March 31, 2005 You have to explain this comment > So I went and bought a new 2nd orifice canister and installed it. < What is an orifice canister, do you mean orifice tube? SIX cans of freon? You know, the correct amount of freon HAS to be installed in the system, TOO much is a really bad thing and can bind the system, freeze the system and damage the system. I NEVER used more than a can or two, if it does not work, it must be done professionally. Airconditioning is a unique skill and as knowledgable as I am about most things, AC is NOT straight forward and I am clueless beyond the basics. If I were you at this point, I would make sure that all joints that I disturbed were Nylogged including the rear of the compressor, that all connections to sensors were good, and I would find a good AC shop and get it leak tested, evacuated and charged. This shop that said you needed a compressor may have blown it, and it was something else and NOT the compressor. I am miffed as to why you have 2 orifice tubes..... You must disconnect the battery to get the compressor to engage You must get to the car and retrieve the codes and post them, you may have a high or low sensor problem, but if you ask me your problem and the wacky things that are going on are OVER MY head via the internet, and it appears to be over yours (that is not a ZING, that is an observation).. Link to comment Share on other sites More sharing options...
KHE Posted April 1, 2005 Report Share Posted April 1, 2005 A012 is the code for the low side temperature circuit problem. You need a shop manual to diagnose/repair this. It may be a bad connection at the sensor or a bad sensor itself. The low side temp. sensor is between the orifice tube and the evaporator on the low side of the system (larger diameter line). Check the connection and clear the code. This is probably what was causing the problem all along.... you replaced a perfectly good compressor.... The correct charge for your system is 2.0 lbs of R-134a. That must be charged into a complete vacuum. If you are charging without vacuuming the system down, there is air in the system and it will not cool/operate. Do not over charge or cooling capacity will be lost and/or components damaged. I would highly recommend taking the car to a Cadillac dealer - they will properly repair the system. The fact that the "mechanic" did not want to work on your car should have indicated that he didn't know his a$$ from third base..... Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
clusco Posted April 1, 2005 Author Report Share Posted April 1, 2005 KHE I really appreciate the code information. Now I know where to start at. The dealership in my town wants $300 just to evacuate and charge my system. That is too expensive. Can you tell me a little more about this sensor... Can you tell me what manual you suggest to use? The Chilton's manual I have won't go into detail about A/C systems or its components whatsoever. Scotty, the only reason I think I may have accidentally put 6 cans is because I thought all of the 1st 3 cans I put in 2 days prior had leaked out because of what this auto shop had told me. The 2nd orifice tube was actually an add-on the dealership made to my car before I owned it (between its 1st year on their lot). I don't know why exactly they added it but they did. It is simply an orifice tube sitting inside of a canister. The canister has 3/8 inch threads on each side that screw onto the A/C line about 15 inches away from the original orifice tube. I'm sure it can't hurt anything. Also, what did you mean by, "You must disconnect the battery to get the compressor to engage"? Do you mean to disconnect it for a certain period of time and then reconnect it? So are you guys telling me that the only way that I can add freon to my system after my sensor problem is solved is to take it to another shop and get them to vacuum it down and add the freon? I can't just add it myself without vacuuming it down again? Link to comment Share on other sites More sharing options...
Scotty Posted April 1, 2005 Report Share Posted April 1, 2005 Sorry. When you get a Low Refrigerant code, the compressor will not engage. In order to get the compressor to engage to add freon, you must clear the code by disconnecting the battery. #1 is the low side thermister, it looks like it is next to the orfice tube...I would look that thermister over. Mike Link to comment Share on other sites More sharing options...
KHE Posted April 1, 2005 Report Share Posted April 1, 2005 KHE I really appreciate the code information. Now I know where to start at. The dealership in my town wants $300 just to evacuate and charge my system. That is too expensive. Can you tell me a little more about this sensor... Can you tell me what manual you suggest to use? The Chilton's manual I have won't go into detail about A/C systems or its components whatsoever. Scotty, the only reason I think I may have accidentally put 6 cans is because I thought all of the 1st 3 cans I put in 2 days prior had leaked out because of what this auto shop had told me. The 2nd orifice tube was actually an add-on the dealership made to my car before I owned it (between its 1st year on their lot). I don't know why exactly they added it but they did. It is simply an orifice tube sitting inside of a canister. The canister has 3/8 inch threads on each side that screw onto the A/C line about 15 inches away from the original orifice tube. I'm sure it can't hurt anything. Also, what did you mean by, "You must disconnect the battery to get the compressor to engage"? Do you mean to disconnect it for a certain period of time and then reconnect it? So are you guys telling me that the only way that I can add freon to my system after my sensor problem is solved is to take it to another shop and get them to vacuum it down and add the freon? I can't just add it myself without vacuuming it down again? The shop manual is the GM service publication available from Helm - www.helminc.com. It is the same manual used by the dealer techs. I buy one for every car I purchase as they pay for themselves the first time you need them. Helm was running a sale - 1995 and older manuals for $30 which is a great deal considering many of them are $120. The Chiltons manuals are virtually worthless...they cover too many years/models in the same manual and dont cover anythign complex such as A/C as you've discovered. They are better than nothing but not much..... You only need ONE orifice tube in the system - that is where the high pressure liquid changes state to a gas near the evaporator. It is in the high pressure line along the firewall. If someone installed a second orivice tube, there is a restriction in the system and it won't cool - period. Can you post a picture of the line that runs along the firewall? That might help in the diagnosis. You must vacuum down the system before adding refrigerant. If you don't, there will be air and moisture in the system. The air will greatly reduce cooling capacity of the system and increase pressures dramatically. The moisture will freeze at the orifice tube and block off the system which will prevent cooling. The moisture will also react with the refrigerant to produce acids that will eat away at the system over time. Disconnecting the negative battery terminal for 30 seconds or so will clear the AC trouble codes so the system will run the compressor and suck in the refrigerant. $300 is highway robbery to evacuate and charge the system....See if you can find an independent A/C shop (not the one you used the first time..!) and have them look at it. Talk to them to get an idea on their competence level before you let them touch your car. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
clusco Posted April 1, 2005 Author Report Share Posted April 1, 2005 Sorry. When you get a Low Refrigerant code, the compressor will not engage. In order to get the compressor to engage to add freon, you must clear the code by disconnecting the battery. #1 is the low side thermister, it looks like it is next to the orfice tube...I would look that thermister over. Mike Guys, I unhooked the low-side thermistor but what do I do from there? What am I looking for here? I know I should bring it in somewhere but the dealership works for $80 an hour and no other mechanic I can find wants to work on the Northstar system. The shop that I brought it to that actualy did the recharge is a large well-established chain but obviously they didn't know what they were doing either. anyway I unhooked the thermistor and cleaned it a bit , put it back in and then unhooked my negative side battery cable for a minute or so and hooked it back. The code still comes up. Should I go to the dealership and buy a new thermistor? By the way, is this the low-side thermistor or the low-side sensor OR are they one in the same? Link to comment Share on other sites More sharing options...
clusco Posted April 1, 2005 Author Report Share Posted April 1, 2005 Is there anyway to test the thermistors with a digital multimeter? Link to comment Share on other sites More sharing options...
Ranger Posted April 1, 2005 Report Share Posted April 1, 2005 no other mechanic I can find wants to work on the Northstar system. A/C is A/C. There is no difference between the Northstar A/C system and a Chevy A/C system. Link to comment Share on other sites More sharing options...
KHE Posted April 1, 2005 Report Share Posted April 1, 2005 no other mechanic I can find wants to work on the Northstar system. A/C is A/C. There is no difference between the Northstar A/C system and a Chevy A/C system. Actually, there is. The basic operating principle is the same but the lower end cars don't use the temp sensors in the lines - they just use a pressure switch on the accumulator to control the compressor cycling. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
JoeM Posted April 1, 2005 Report Share Posted April 1, 2005 Isnt that what i said? Link to comment Share on other sites More sharing options...
KHE Posted April 2, 2005 Report Share Posted April 2, 2005 I don't have a '95 manual. The '96 manual is different in that the codes are OBD-2. Possibly someone with a '95 shop manual can post the troubleshooting chart for the A012 code. Another thought would be to unplug the sensor and measure the resistance across the sensor terminals. If it is infinite or if it is 0, you might have a bad sensor. But....I would recommend reviewing the '95 manual. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Scotty Posted April 5, 2005 Report Share Posted April 5, 2005 Kevin what do you think about this, do you think the vacuum pump would be adequate? Thanks, Mike http://www.etoolcart.com/index.asp?PageAct...ROD&ProdID=7013 Link to comment Share on other sites More sharing options...
navion Posted April 5, 2005 Report Share Posted April 5, 2005 Scotty, The air powered vac will produce about 28 in. Hg of vacuum. This is not quite as good as a quality vacuum pump, but should be adequate for occasional car use. It will consume about 4 to 5 CFM of air at 90 PSI (depending on the unit.) So be sure that your aircompressor is up to the task. I would run the unit at least an hour to dry the system out. Longer if it has been open to the atmosphere and/or empty of freon. Britt Britt Link to comment Share on other sites More sharing options...
Scotty Posted April 5, 2005 Report Share Posted April 5, 2005 Thanks Britt, how did you pick up that the vacuum pump works with my compressor, I don't see reference to that... Thanks for the info, Mike Link to comment Share on other sites More sharing options...
KHE Posted April 5, 2005 Report Share Posted April 5, 2005 You'll need a compressor with a lot of CFMs to run that air vac.....I certainly wouldn't use one of the oil-less compressors.....You need to vacuum the system for at lease 45 mins. and that means the compressor will be running continuously for that time. I bought my 5cfm direct drive vacuum pump used about three years ago for $157 which was a good price. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
KHE Posted April 5, 2005 Report Share Posted April 5, 2005 Thanks Britt, how did you pick up that the vacuum pump works with my compressor, I don't see reference to that... Thanks for the info, Mike It works on the venturi principle to create the vacuum. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Scotty Posted April 5, 2005 Report Share Posted April 5, 2005 Thanks Britt, how did you pick up that the vacuum pump works with my compressor, I don't see reference to that... Thanks for the info, Mike It works on the venturi principle to create the vacuum. Kevin and Britt, am I wasting my money here? Thanks, Mike Link to comment Share on other sites More sharing options...
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