ac "odd" behavior?
From : just another
Q: .... but ive been surprised what normal is before. i have a 97 ram van b2500 standard ac front only. under idle or cruising conditions all is fine & ac comes through the dashboard fairly strong might need recharge. under acceleration or hillclimbing load the ac comes through the lower heater vents. when i back off on the throttle the ac again comes through the dashboard. when the acs coming through the lower vents nothing comes out the dashboard. so is this normal behavior if not what would cause it i know that the heater/ac are a single black-box unit but my haynes manual doesnt describe it very well. .
Replies:
From : max dodge
vent position floor panel defroster depends on a set of vacuum actuated doors. under hard acceleration vaccum changes and thus so does the direction the a/c blows. this is normal. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author ... but ive been surprised what normal is before. i have a 97 ram van b2500 standard ac front only. under idle or cruising conditions all is fine & ac comes through the dashboard fairly strong might need recharge. under acceleration or hillclimbing load the ac comes through the lower heater vents. when i back off on the throttle the ac again comes through the dashboard. when the acs coming through the lower vents nothing comes out the dashboard. so is this normal behavior if not what would cause it i know that the heater/ac are a single black-box unit but my haynes manual doesnt describe it very well. .
From : just another
max dodge max340@verizon.net wrote vent position floor panel defroster depends on a set of vacuum actuated doors. under hard acceleration vaccum changes and thus so does the direction the a/c blows. this is normal. thanks. itll probably be less annoying after i recharge the ac. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author ... but ive been surprised what normal is before. i have a 97 ram van b2500 standard ac front only. under idle or cruising conditions all is fine & ac comes through the dashboard fairly strong might need recharge. under acceleration or hillclimbing load the ac comes through the lower heater vents. when i back off on the throttle the ac again comes through the dashboard. when the acs coming through the lower vents nothing comes out the dashboard. so is this normal behavior if not what would cause it i know that the heater/ac are a single black-box unit but my haynes manual doesnt describe it very well. .
From : Annonymous
writes vent position floor panel defroster depends on a set of vacuum actuated doors. under hard acceleration vaccum changes and thus so does the direction the a/c blows. this is normal. true this is how the vents work but my bet is if youve had this vehicle for a while that this is possibly not normal behavior to you else you wouldnt be asking about it now after so many years of ownership. it hasnt always done this right my own guess is youve developed a vacuum leak possibly due to a broken vacuum line somewhere. just where would be anyones guess but one of the more common places is right at the top of your cruise control vacuum cannister. if your vehicle has cruise does it still work if not then youve found your leak. fix the leak replace the line and you will have fixed your cruise and your ac. ;- .
From : tbone
that is complete bullshit and does not indicate normal behavior. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. -- if at first you dont succeed youre not cut out for skydiving vent position floor panel defroster depends on a set of vacuum actuated doors. under hard acceleration vaccum changes and thus so does the direction the a/c blows. this is normal. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author ... but ive been surprised what normal is before. i have a 97 ram van b2500 standard ac front only. under idle or cruising conditions all is fine & ac comes through the dashboard fairly strong might need recharge. under acceleration or hillclimbing load the ac comes through the lower heater vents. when i back off on the throttle the ac again comes through the dashboard. when the acs coming through the lower vents nothing comes out the dashboard. so is this normal behavior if not what would cause it i know that the heater/ac are a single black-box unit but my haynes manual doesnt describe it very well. .
From : max dodge
that is complete bullshit and does not indicate normal behavior. its been normal behavior in chrysler vehicles since the early 70s my dart does it my cordoba does it and my lebaron does it. the only vehicle i have that doesnt do it is the ram and thats got a vacuum pump on it instead of engine vacuum. this is another case of you spouting off without thinking. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it for someone who vehemently questioned the engineering of certain electrical circuits when queried about a voltage drop your faith in their ability has certainly improved. what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author that is complete bullshit and does not indicate normal behavior. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. -- if at first you dont succeed youre not cut out for skydiving vent position floor panel defroster depends on a set of vacuum actuated doors. under hard acceleration vaccum changes and thus so does the direction the a/c blows. this is normal. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author ... but ive been surprised what normal is before. i have a 97 ram van b2500 standard ac front only. under idle or cruising conditions all is fine & ac comes through the dashboard fairly strong might need recharge. under acceleration or hillclimbing load the ac comes through the lower heater vents. when i back off on the throttle the ac again comes through the dashboard. when the acs coming through the lower vents nothing comes out the dashboard. so is this normal behavior if not what would cause it i know that the heater/ac are a single black-box unit but my haynes manual doesnt describe it very well. .
From : big al
that is complete bullshit and does not indicate normal behavior. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. usually its a cracked hose. most ac systems have a small reservoir somewhere and a check valve. no idea what a van has. al .
From : max dodge
usually its a cracked hose. most ac systems have a small reservoir somewhere and a check valve. no idea what a van has. ac systems have no reservoir for vacuum. the entire vacuum system has a reservoir which may or may not be big enough to counter a wot application particularly on a van application. thus since the reservoir is for the entire system not just the hvac controls it is entirely possible that fluctuations in the system will show up as momentary changes in how the hvac doors are positioned. obviously a diesel ram would be different since no engine systems use vacuum unlike the gassers. obviously since this is a van it hasnt got a diesel. it is interesting to note that the troubleshooting section on the hvac vacuum system claims that a system that works well at idle may not work well at high engine speeds. meanwhile you two are suggesting vacuum leaks and such as the cause. you are aware i hope that a vacuum leak would cause the hvac controls to operate erratically most of the time not just at low vacuum events. also if the vacuum system has a leak some sort of loss in performance of the engine would result. most likely symptons would be loss of power stumbling or backfiring. but im sure you both know better than me at least in your own minds. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author that is complete bullshit and does not indicate normal behavior. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. usually its a cracked hose. most ac systems have a small reservoir somewhere and a check valve. no idea what a van has. al .
From : tbone
that is complete bullshit and does not indicate normal behavior. its been normal behavior in chrysler vehicles since the early 70s my dart does it my cordoba does it and my lebaron does it. the only vehicle i have that doesnt do it is the ram and thats got a vacuum pump on it instead of engine vacuum. so you are comparing relics from the 70s to a modern truck!!!! my 97 does not have a vacuum pump and it never does that and come to think of it neither did either one of my magnums 78 and 79. this is another case of you spouting off without thinking. me lol pkb. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it for someone who vehemently questioned the engineering of certain electrical circuits when queried about a voltage drop your faith in their ability has certainly improved. once again resorting to spin i see. i never claimed that the engineers were at fault for the undersized wiring that would be you in your lame attempt to cover for not understanding a simple voltage drop. what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. just because something is difficult to find doesnt make the problems it causes normal unless of course you suck as a mechanic and use crap like this as an excuse not to try and fix it. -- if at first you dont succeed youre not cut out for skydiving .
From : tbone
so you are comparing relics from the 70s to a modern truck!!!! my 97 does not have a vacuum pump and it never does that and come to think of it neither did either one of my magnums 78 and 79. your 97 wouldnt have a vacuum pump its not a diesel. to most of us that actually know somehting this fact would have been obvious. lol are you really this desperate who am i kidding of course you are. i am well aware of why my truck does not have or need one and my point was that even without it and depending on nothing but engine vacuum my climate control is working exactly as it is supposed to without airflow interruption due to either acceleration or heavy load. if you had the knowledge you claim to then you would be able to argue on valid points instead of desperate reaches like this. oh thats right you have no valid argunment and need to once again resort to spin and insults. just because something is difficult to find doesnt make the problems it causes normal unless of course you suck as a mechanic and use crap like this as an excuse not to try and fix it. might be why you arent a mechanic and instead think a vacuum system is perfect all the time. more desperate reaches and complete bullshit. what you said above means absolutely nothing. what does thinking that a vacuum system is perfect all of the time have to do with the problem and where did i ever say this while they dont have to be perfect to function to claim the behavior from a leak is normal is just ignorant. if you actually know mechanical systems you would know that a vacuum system is the most difficult to keep leak free and also the most difficult in which to find the leak. lol why is that i believe you may think that because they exceed you skill level. what makes it harder to diagnose than anything else the check valve take all of about 10 seconds and the rest of it within a half an hour provided you know how to do it but for you it might take all day so i can see why you treat it the way you do. further you would know that a perfect vacuum can cause as many problems as a system that has too big a leak. hahahahahahahaha you really are too funny. by definition this is impossible. obviously since you decided against arguing with my technical fact youve got nothing of actual facts for a rebuttal. what technical fact i have yet to see a single one. your examples of old relics you own are not facts just further examples of other problems using a very different system. you then come up with complete hogwash that a perfect system will cause as many problems as a defective one when even by definition the word perfect means without flaw and therefore would be unable to have problems. then you say because something is hard to fix a results of the problem should be thought of as a normal condition. yea you have some killer technical facts here. good luck with your credibility. my credibility with the crap you just spewed out here you should be the last one to talk about anyones credibility. -- if at first you dont succeed youre not cut out for skydiving .
From : ed
have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. i use a can of carberator cleaner to find vacuum leaks. with the engine running spray the carb cleaner on the vacuum hoses. you can hear the engine slow when the carb cleaner enters the through the vacuum leak. i havent had to do that to a fuel injected engine but i dont think it would cause any harm. .
From : max dodge
on sun 09 jul 2006 180215 gmt max dodge max340@verizon.net wrote brian what snobrain is referencign aout releasing heat energy too soon is due to cam timing and has nothing to do with headers. hey wtf is the word below you are so quick to correct others..... responce geeze roy resorting to spelling errors. as sad as it may be snowman is completely correct here. really care to show me think about it roy. because there is some resistance in the stock exhaust manifold along with the cc and factory exhaust the exhaust valve timing has been set up to not only deal with it but to try and take advantage of it. if you then radically change those flow characteristics do you not think that the valve timing will now be incorrect. these are not engines from the late 70s and 80s. these engines are now computer designed to operate at peak efficiency within a given rpm range with the emission controls and components that they are now using unlike engines of the past that were set up by manual flow tests and trial and error from race engines to run with minimum back pressure that were then buried under restrictive emission controls virtually unchanged due to the big three sitting on their hands to the last possible minute hoping the epa would back down. now in a perfect world such as maxworld there would be no such things effecting exhaust and intake flow such as mass inertia compression expansion and resistance but we do not live in that world. i would say that they open the exhaust valve a little sooner to allow more time for the exhaust gasses to escape while using the existing back pressure and resistance of the stock manifold to prevent thermal expansion loss. if you then remove a significant amount of that back pressure you would have that valve opening to soon and blowing some of what should be developing power right out of the exhaust. -- if at first you dont succeed youre not cut out for skydiving . 222 319889 vqsug.2334$pr4.1592@trndny01 so you are comparing relics from the 70s to a modern truck!!!! my 97 does not have a vacuum pump and it never does that and come to think of it neither did either one of my magnums 78 and 79. your 97 wouldnt have a vacuum pump its not a diesel. to most of us that actually know somehting this fact would have been obvious. just because something is difficult to find doesnt make the problems it causes normal unless of course you suck as a mechanic and use crap like this as an excuse not to try and fix it. might be why you arent a mechanic and instead think a vacuum system is perfect all the time. if you actually know mechanical systems you would know that a vacuum system is the most difficult to keep leak free and also the most difficult in which to find the leak. further you would know that a perfect vacuum can cause as many problems as a system that has too big a leak. obviously since you decided against arguing with my technical fact youve got nothing of actual facts for a rebuttal. good luck with your credibility. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author that is complete bullshit and does not indicate normal behavior. its been normal behavior in chrysler vehicles since the early 70s my dart does it my cordoba does it and my lebaron does it. the only vehicle i have that doesnt do it is the ram and thats got a vacuum pump on it instead of engine vacuum. so you are comparing relics from the 70s to a modern truck!!!! my 97 does not have a vacuum pump and it never does that and come to think of it neither did either one of my magnums 78 and 79. this is another case of you spouting off without thinking. me lol pkb. do you think that the engineers did not take the vacuum drop typical with hard load or acceleration into account when they designed it for someone who vehemently questioned the engineering of certain electrical circuits when queried about a voltage drop your faith in their ability has certainly improved. once again resorting to spin i see. i never claimed that the engineers were at fault for the undersized wiring that would be you in your lame attempt to cover for not understanding a simple voltage drop. what this does indicate is either a defective check valve used to prevent those vacuum changes from effecting air flow or a vacuum leak after it. have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. just because something is difficult to find doesnt make the problems it causes normal unless of course you suck as a mechanic and use crap like this as an excuse not to try and fix it. -- if at first you dont succeed youre not cut out for skydiving
From : max dodge
using the carb cleaner is fine until you try it on the hvac stuff under the dash. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. i use a can of carberator cleaner to find vacuum leaks. with the engine running spray the carb cleaner on the vacuum hoses. you can hear the engine slow when the carb cleaner enters the through the vacuum leak. i havent had to do that to a fuel injected engine but i dont think it would cause any harm. .
From : ed
does carb cleaner cause a problem with the hvac or does it just make a mess inside the cab using the carb cleaner is fine until you try it on the hvac stuff under the dash. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. i use a can of carberator cleaner to find vacuum leaks. with the engine running spray the carb cleaner on the vacuum hoses. you can hear the engine slow when the carb cleaner enters the through the vacuum leak. i havent had to do that to a fuel injected engine but i dont think it would cause any harm. .
From : max dodge
does carb cleaner cause a problem with the hvac or does it just make a mess inside the cab carb cleaner tends to do a number on the soft plastic of the interior plus its a bit difficult to get it to go where you want under the dash. add in the effort of getting to see what you are hitting and the risk of getting a face full and its a less than great idea. the leaks these other guys are so hip to find tend to be found in the vacuum switch itself making it hard to fix. replacement is the best option and the device can be fairly pricey. the reason i call it normal is because a vacuum switch rarely is sealed in the sense that most of us know. itll only wear further so the new one may be bad in weeks or years depending on a number of factors. hard acceleration will drop vacuum signal and a leaky switch will allow it to dissapate completey in some cases. so is it normal or is it a gotta replace that because everything works perfectly in my truck despite its age some people think its cool to look knowledgable. i figure its best to call it like it is... a vacuum system without a leak is not normal its a rare bird. however your carb clean trick is tried and true for all things in the engine compartment and is very effective there. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author does carb cleaner cause a problem with the hvac or does it just make a mess inside the cab using the carb cleaner is fine until you try it on the hvac stuff under the dash. -- max there are four boxes to be used in defense of liberty soap ballot jury and ammo. please use in that order. -ed howdershelt author have fun chasing down a vacuum leak etc. for the amount of time you put into trying to make a system perfect youll realize that this minor imperfection is normal. i use a can of carberator cleaner to find vacuum leaks. with the engine running spray the carb cleaner on the vacuum hoses. you can hear the engine slow when the carb cleaner enters the through the vacuum leak. i havent had to do that to a fuel injected engine but i dont think it would cause any harm. .
From : tbone
usually its a cracked hose. most ac systems have a small reservoir somewhere and a check valve. no idea what a van has. ac systems have no reservoir for vacuum. the entire vacuum system has a reservoir which may or may not be big enough to counter a wot application particularly on a van application. thus since the reservoir is for the entire system not just the hvac controls it is entirely possible that fluctuations in the system will show up as momentary changes in how the hvac doors are positioned. where exactly is this system wide reservoir and exactly how does it work without a check valve obviously a diesel ram would be different since no engine systems use vacuum unlike the gassers. obviously since this is a van it hasnt got a diesel. wow you are really bright today. did you have to look this one up it is interesting to note that the troubleshooting section on the hvac vacuum system claims that a system that works well at idle may not work well at high engine speeds. yea they are referring to changing modes at high engine speeds not steady state operation but you knew that right! meanwhile you two are suggesting vacuum leaks and such as the cause. you are aware i hope that a vacuum leak would cause the hvac controls to operate erratically most of the time not just at low vacuum events. hahahaha complete bs. only if the leak were severe enough but a minor leak would cause no erratic operation under high vacuum conditions. also if the vacuum system has a leak some sort of loss in performance of the engine would result. most likely symptons would be loss of power stumbling or backfiring. again only with a major leak such as a broken line and even then i doubt that the line that feeds the hvac controls would be big enough to cause thatlevel of a vacuum leak and if it were somehow that severe the hvac controlls wouldnt work at all. then you keep forgetting that if the check-valve is the problem there would be no detectable symptoms as far as the engine was concerned. you really dont know shit about this do you but im sure you both know better than me at least in your own minds. we do know better than you both in our minds and in the minds of just about anyone that understands these systems with the crap you spewed out above. -- if at first you dont succeed youre not cut out for skydiving .