Scotty Posted June 22, 2005 Author Report Share Posted June 22, 2005 Scotty/KHE, I just spoke to a fellow employee that works on automotive A/C on the side and he stated the plastic blade in front of the orifice tube should have a small arrow embossed on it, showing direction of flow. He agrees with KHE that the long end should be inserted into the evaporator as best has he recollects. He stated the very small prongs at the end of the orifice tube (near the tips of the needle nose pliers in the pic) are 'captured' when you use a special tool for extracting the device. He also agrees that other than interference issues, it should not make a difference in performance. When I replaced mine, I did it per the picture in the link I posted above, which also agreed with how the original one was installed at the factory. I guess it can vary. KHE said the long end goes toward the CONDENSER - just the opposite of most cars. If you reverse the orientation, the sensor will be damaged as it will interfere with the o-tube. I think that was the root cause of the premature sensor failure in Scotty's car. If you look at the picture of Scotty's original o-tube, all the trash from the failed compressor is on the long end which is the condenser end. YES KEVIN you are correct, the long end has all of the debris coming FROM the compressor THROUGH the condensor, that end was facing the condensor! THAT PHOTO is what made me realize that I had it in wrong. And YES it did physically interfere with the Evaporator Inlet Temp Sensor and damaged TWO of them.... Insert a BIG DUH for me right here! Thanks, this thread contains lots of goodies now I believe! I learned a lot here! Link to comment Share on other sites More sharing options...
Scotty Posted June 22, 2005 Author Report Share Posted June 22, 2005 Hi Scotty Hey sh-- happens but all in all you did good. You need to get a set of gm manuals CHeers Jim Jim, I do have a 1996 service manual is that what you mean? I just screwed up NOT realizing that the orifice tube had a correct orientation due to my inexperience, I put it in the way it "looked" right. In my defense I have seen that others have made the same mistake, I provided a link above... "Lessons learned are like bridges burned you only need but cross them but once"! Dan Fogelberg Link to comment Share on other sites More sharing options...
JIMDTS Posted June 22, 2005 Report Share Posted June 22, 2005 Hi Scotty It's an easy mistake to make I didn't know what manuals you were using. On all the GM cars that I have ever owned I always purchase the GM repair manuals just in case I need to do something on the car It sure beats the chiltons and other manuals. It's too bad they did not make a shoulder inside that line where the orifice could only fit one way but it would add to the cost All in all you did a good job I have installed a few a/c system parts in other cars that i have owned but that was a long time ago.. Jim Link to comment Share on other sites More sharing options...
Scotty Posted June 22, 2005 Author Report Share Posted June 22, 2005 Thanks Jim, this was all new to me, I couldnt have done it without this board! Link to comment Share on other sites More sharing options...
Scotty Posted June 22, 2005 Author Report Share Posted June 22, 2005 I am having one "problem" or "question", the compressor is not cycling on and off, should it this time of year? I even turned the temp up to 74 degrees and it did not cycle.... Maybe my high pressure sensor is stuck not providing the correct info? No codes... When I put it in ECON the compressor goes off.. which is normal... Any thoughts? Link to comment Share on other sites More sharing options...
Northstar Posted June 22, 2005 Report Share Posted June 22, 2005 When I first start mine up it stays on for a while but it will start to cycle after the inside starts getting cold. Yours should cycle after the initial demand has been met. My temps are 95f right now. Link to comment Share on other sites More sharing options...
Scotty Posted June 22, 2005 Author Report Share Posted June 22, 2005 Thanks Northstar Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 I was just outside, I let it sit for about 10 minutes, and the compressor ran constantly, no on/off cycle. What causes the cycling? I don't have a Tech 1 to see what the sensors are reading so im in the dark. My guess is that the something is not giving the correct info to the ACM. Is there any way to observe ACM readings in the DIC? Anyone have any ideas on this? The pipe is warm before the orifice tube and cold after it. AC is working fine.. When I WOT or put it in ECON the compressor stops as designed. What cycles the compressor Temperature or Pressure? Link to comment Share on other sites More sharing options...
Ranger Posted June 23, 2005 Report Share Posted June 23, 2005 I believe it is the low side tempurature sensor that does the cycling. I just saw it the other day. Look in the A/C section of the manual where it discribes each component of the system and what it does. High side pressure controls the fans, low side pressure disables the compressor as I recall but check it to verify. Link to comment Share on other sites More sharing options...
KHE Posted June 23, 2005 Report Share Posted June 23, 2005 I am having one "problem" or "question", the compressor is not cycling on and off, should it this time of year? I even turned the temp up to 74 degrees and it did not cycle.... Maybe my high pressure sensor is stuck not providing the correct info? No codes... When I put it in ECON the compressor goes off.. which is normal... Any thoughts? Rev the engine to 1500-2000 RPM and I will bet the compressor cycles. I think there is a way to view the compressor status via the onboard diagnostics. BTW, It is a very easy mistake to reverse the orifice tube..... Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 I believe it is the low side tempurature sensor that does the cycling. I just saw it the other day. Look in the A/C section of the manual where it discribes each component of the system and what it does. High side pressure controls the fans, low side pressure disables the compressor as I recall but check it to verify. Thanks I will look it over again. I replaced the Evaporator Inlet Temp Sensor and the Low Pressure Switch. It would be terrific if I could replace that sensor without depressurizing the system again but I doubt it. Is is possible for these sensors to mess up and not set a code? Thanks Ranger Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 I am having one "problem" or "question", the compressor is not cycling on and off, should it this time of year? I even turned the temp up to 74 degrees and it did not cycle.... Maybe my high pressure sensor is stuck not providing the correct info? No codes... When I put it in ECON the compressor goes off.. which is normal... Any thoughts? Rev the engine to 1500-2000 RPM and I will bet the compressor cycles. I think there is a way to view the compressor status via the onboard diagnostics. BTW, It is a very easy mistake to reverse the orifice tube..... I think you may be right about that, when I accelerate from idle the compressor kicks out and I don't think thats related to any WOT condition. I think it can stay on for 45 seconds and then kick out, I have not be able to see it kick out on its own yet. What I am afraid of is the system freezing because it does not kick out... and damaging the evaporator. I suppose if I had a temp sensor problem I would get a code. Maybe the exterior temp is commanding the compressor to be on. Thanks Kevin about the orifice tube, it certainly was easy! What do you think about this LACK of cycling? What damage can be caused if I have a problem? Thanks I am tempted to buy a TECH 1 Link to comment Share on other sites More sharing options...
Ranger Posted June 23, 2005 Report Share Posted June 23, 2005 I believe it is the low side tempurature sensor that does the cycling. I just saw it the other day. Look in the A/C section of the manual where it discribes each component of the system and what it does. High side pressure controls the fans, low side pressure disables the compressor as I recall but check it to verify. Thanks I will look it over again. I replaced the Evaporator Inlet Temp Sensor and the Low Pressure Switch. It would be terrific if I could replace that sensor without depressurizing the system again but I doubt it. Is is possible for these sensors to mess up and not set a code? Thanks Ranger My guess would be no. Link to comment Share on other sites More sharing options...
KHE Posted June 23, 2005 Report Share Posted June 23, 2005 I am having one "problem" or "question", the compressor is not cycling on and off, should it this time of year? I even turned the temp up to 74 degrees and it did not cycle.... Maybe my high pressure sensor is stuck not providing the correct info? No codes... When I put it in ECON the compressor goes off.. which is normal... Any thoughts? Rev the engine to 1500-2000 RPM and I will bet the compressor cycles. I think there is a way to view the compressor status via the onboard diagnostics. BTW, It is a very easy mistake to reverse the orifice tube..... I think you may be right about that, when I accelerate from idle the compressor kicks out and I don't think thats related to any WOT condition. I think it can stay on for 45 seconds and then kick out, I have not be able to see it kick out on its own yet. What I am afraid of is the system freezing because it does not kick out... and damaging the evaporator. I suppose if I had a temp sensor problem I would get a code. Maybe the exterior temp is commanding the compressor to be on. Thanks Kevin about the orifice tube, it certainly was easy! What do you think about this LACK of cycling? What damage can be caused if I have a problem? Thanks I am tempted to buy a TECH 1 I wouldn't be concerned at this point. Keep a thermometer in the center duct and watch the temp. As long as the outlet temp. is above 35 degrees (the air warms up a few degrees by the time it exits the vents) you shouldn't have to worry about the evaporator freezing. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 Thanks Kevin... You know I forgot to mention, having replaced the water pump tensioner, the idler wheel, the serp belt with a goodyear gatorback and the serp tensioner the engine is SO quiet on the highway, its like a new car! Link to comment Share on other sites More sharing options...
Matt Posted June 23, 2005 Report Share Posted June 23, 2005 Way to go Mike. I'm happy for you. Enjoy the cool. There are lots of hot days on the way. Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 Thanks Matt, this was a tricky one, I am still not 100% confident that is working correct yet, we will see... I learned a lot however and that makes it all worth it, Thanks Link to comment Share on other sites More sharing options...
Matt Posted June 23, 2005 Report Share Posted June 23, 2005 Hey ya know we all learned from your hard work. Look at me, I'm now trouble shooting my Moms car AC. I never would have thought to do it if it was not for the things that go on here. Thanks Mike!! I know what ya mean about not trusting it yet, That is normal. I'm still watching my charging volts all the time. LOL I do not trust that yet either. LOL It will be Ok Mike. I have faith in ya buddy... I got to run Mike. Honey do project time ... Good Night. catch ya in the AM... Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 Thanks Matt, this board is great isn't it? Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 Well good news! I went out today, to fill up my tires (with summer air)... and started my car while I was doing it, AND low and behold, my AC compressor started cycling on and OFF! Yeah! The outside temp is in the 60's so maybe that has something to do with it! Happy Days Are Here Again! Thanks Kevin and all who helped and supported my project! Mike Link to comment Share on other sites More sharing options...
Ranger Posted June 23, 2005 Report Share Posted June 23, 2005 Mike, Regarding your question about cycling, if found this quite interesting. "The system is cycled to maintain the most useful pressure for commonly encountered temperatures. With a FULL charge, the system will cycle very frequently in cooler temperatures, and sometimes will not have the pressure to EVER come on. That is how the CCOT systems work, and why they cycle the clutch a lot. The thermal expansion valve systems cycle the clutch less. If the charge is proper, in high temperatures, you might never see a time when the compressor clutch cycles off, until the cabin is cool, or the temperature drops outside. If the charge is too low, it'll cycle frequently to keep ice away." Found it on this site http://autoacrepairs.com/aboutall.html under "Cycle Switch Info". Lots of good information on this site for us ametures. Link to comment Share on other sites More sharing options...
Scotty Posted June 23, 2005 Author Report Share Posted June 23, 2005 Ranger Thanks, that explains why it was not cycling at 80 degrees but it was cycling this morning at 66 degrees... It seems to be working great and my coolant temps are looking really good... Thanks for looking out for me! Mike Link to comment Share on other sites More sharing options...
runar Posted June 25, 2005 Report Share Posted June 25, 2005 Hi Scotty. Good to see you got it all working. It has been a very interesting read indeed. I ordered my exhaust mainfold from Sacramento. Very nice people there. If I am pleased with their service, I will put their webaddress here. I think they recycle only Cadillac parts. Regards Runar Link to comment Share on other sites More sharing options...
Matt Posted June 25, 2005 Report Share Posted June 25, 2005 indeed, a very interesting read. Sounds like it's working great... Link to comment Share on other sites More sharing options...
WarrenJ Posted June 25, 2005 Report Share Posted June 25, 2005 Sheesh, Scotty . . . . You may just have set a record for the LLLOOONNNGGGEEESSSTTT post. 12 pages and still counting! And, oh yeah, you're correct Mike, this board IS GREAT! Our moderator does us all a great service. Regards, Warren P.S. Unless I'm mistaken, Bruce's birthday is October 29th. I've bookmarked it! You can expect a reminder. There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
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