air cond. not working

my 97 lumina air wont work.. the compresor wont even click. relay checks ok.. was ok last year.. i just put an intake gasket on, mabe i knocked a wire off.. any help..

Make sure you didn't forgot to hook up a ground wire...probe the compressor's pigtail with a test light and see if you have a ground but no hot, or hot and no ground when it's on...then you'll know at least which is the problem.

Make sure the pigtail didn't just get corroded over the winter too...happens occaisionally...you pull the plug off and put it back on, and it starts working...

Make sure the pigtail didn't just get corroded over the winter too...happens occaisionally...you pull the plug off and put it back on, and it starts working...
i checked all the relays and the fuses, i will check the connector for the compressor, this thing wont even click.. cold low freon doit?

Yes there is a low pressure cutoff switch...won't let the compressor run if the system is too low...

Yes there is a low pressure cutoff switch...won't let the compressor run if the system is too low...
jeff.. theres nothing at the compressor,, i took the pigtail off and nothing no current. i run a hot wire from the battery, to the compessor and it kicked in.. the haynes book said check the pigtail at the accumulator, and jump it. theres 3 wires on it red gray black, when i jump the gray and black the engine stops runing, when i jump the black or gray it does nothing.. when i put my test lite on the plug im geting current..is there any other grounds?

I'm afraid to suggest any more...I haven't worked on A/C systems since they got more complex and had connections to the ECM (which is why I suspect it died when you crossed it up)...

If one wire coming off the switch matches one at the compressor, I'd think that should be the one you need to to jump power to...did you verify ground at one side of the compressor plug?

I'm afraid to suggest any more...I haven't worked on A/C systems since they got more complex and had connections to the ECM (which is why I suspect it died when you crossed it up)...

If one wire coming off the switch matches one at the compressor, I'd think that should be the one you need to to jump power to...did you verify ground at one side of the compressor plug?
there is a ground at one side of the compressor.. the haynes manual says that if i take the pigtail of the accumulator and jump the wires it should kick the compressor on.. but as i said it stops the engine.. could the pcm be the problem? if its low freon the manual states the compressor has to be working, to put freon in..

there is a ground at one side of the compressor.. the haynes manual says that if i take the pigtail of the accumulator and jump the wires it should kick the compressor on.. but as i said it stops the engine.. could the pcm be the problem? if its low freon the manual states the compressor has to be working, to put freon in..

It doesn't HAVE to be...most times they will kick on as soon as the refigerant starts to go in, just doesn't go in very fast with the compressor off...

You can get an R134a recharge kit very cheap and shoot it, just to see if it will start up and run, or starts blowing out of the system like crazy somewhere..

If the system is so low that the compressor won't start, then just the pressure of a charge can hooked to it will bring system pressure up high enough to close the low pressure switch and start the compressor...may take a few seconds to a minute before it does, but I've not seen one fail to start unless there was something else wrong...running cold water over the condensor will make it draw it in faster too...

If you have power as far as the low pressure switch, and you were able to start the compressor directly, it sounds like the system is low charge or the switch died...I doubt the ECM is involved...

It doesn't HAVE to be...most times they will kick on as soon as the refigerant starts to go in, just doesn't go in very fast with the compressor off...

You can get an R134a recharge kit very cheap and shoot it, just to see if it will start up and run, or starts blowing out of the system like crazy somewhere..

If the system is so low that the compressor won't start, then just the pressure of a charge can hooked to it will bring system pressure up high enough to close the low pressure switch and start the compressor...may take a few seconds to a minute before it does, but I've not seen one fail to start unless there was something else wrong...running cold water over the condensor will make it draw it in faster too...

If you have power as far as the low pressure switch, and you were able to start the compressor directly, it sounds like the system is low charge or the switch died...I doubt the ECM is involved...
the low pressure switch is what i think too.. if the clutch was gone on the compressor it wouldnt run when i jump it.. if the pcm or relay was at fault, i wouldnt get any fire to the switch on the accumulator.. l guess i will try freon and hope it kicks on.. thanks for the help..

R134a...I suspect you are using the term Freon generically, but just in case...

Good luck, tell us what happens...

R134a...I suspect you are using the term Freon generically, but just in case...

Good luck, tell us what happens...
jeff.. just bought the 134a kit at auto zone, hooked it up it took less than a minute to empty the 19 oz can.. compressor still never come on , i see no leakage.. something not right..

If you have any more, try putting it in with the engine off so you can hear it blowing out...have a door open too in case it's the evap core..

If you have any more, try putting it in with the engine off so you can hear it blowing out...have a door open too in case it's the evap core..
i did that,, if its leaking i cant find it, could the system just be totaly dry, i had good air last year.. i never had it recharged since i bought it new.. is the switch at the accumulator replacable? could it be the switch on the dash? how would i check ?

Deos your recharge kit have a gauge? Does it show static pressure in the system with the motor off? How much?

Deos your recharge kit have a gauge? Does it show static pressure in the system with the motor off? How much?
jeff.. i give up on it.. when i get a chance i will take it in to see what the trouble is.. i read the manual and the tem sensor, i just replaced and the cooling fans all hook togeather in the pcm.. i think its electrical. but im stumpd..thanks for your help..

i dont think it is low on refrig, 19oz would be enough to make it cycle , and one thing if ever your refrig is low you have a leak some where, what has me stumped is why the it cuts the engine off, i belive you have a short some where wish i had this earlier to help, i do a/c work but on big trucks but most systems are pretty much the same. while i use nitrogen to check for leaks, the little shot cans you can buy of the dye work great now, and do not hurt the system the you dont have to have a big uv light the little pen lights work great,even though i dont think that is your problem. as far as the evap leaking that is about one in a hundred chance , cause they are not exposed to the outside elements, but caustic acid does build around them since they are enclosed and in wet conditions. i would look for short in the wiring, you also didnt say how you jumped the system, if you removed your plug in, then plug it bcak end and splice into the system and see if it kills the system and this will tell you if it is further up in the harness if it still does it, element the wire from ecm and and run another wire(jumper) form a/c side of ecm and see if it what it does, but remember when running a jumper always use a circut breaker in the jumper on a/c's i usually use a ten amp, and i hold it in my hand so i can feel the heat on it. hope this helps some just remember some of the most simple things we over look cause the most problems.

i dont think it is low on refrig, 19oz would be enough to make it cycle , and one thing if ever your refrig is low you have a leak some where, what has me stumped is why the it cuts the engine off, i belive you have a short some where wish i had this earlier to help, i do a/c work but on big trucks but most systems are pretty much the same. while i use nitrogen to check for leaks, the little shot cans you can buy of the dye work great now, and do not hurt the system the you dont have to have a big uv light the little pen lights work great,even though i dont think that is your problem. as far as the evap leaking that is about one in a hundred chance , cause they are not exposed to the outside elements, but caustic acid does build around them since they are enclosed and in wet conditions. i would look for short in the wiring, you also didnt say how you jumped the system, if you removed your plug in, then plug it bcak end and splice into the system and see if it kills the system and this will tell you if it is further up in the harness if it still does it, element the wire from ecm and and run another wire(jumper) form a/c side of ecm and see if it what it does, but remember when running a jumper always use a circut breaker in the jumper on a/c's i usually use a ten amp, and i hold it in my hand so i can feel the heat on it. hope this helps some just remember some of the most simple things we over look cause the most problems.
theres a three wire swich by the accumulater that the haynes book says if its low on r134 if jumped it would kick the compressor on.. if i jump it one way the fans come on, if i jump it the other way the engine stops.. also the book say to check the compresser run a jumper from the battery to compresser and when i do the clutch kicks in.. is there any kind of dye cheap or what else can i use to check for leaks. that r134 cost $29.00 at auto zone.. i will just keep tinkering with it untill i get pissed off and take it to the shop...

yes there is a kit costs around 16 bucks bought one to try , it came with small can of dye and a pen uv light, even brightier than my big uv, but if you have full charge the in sytem you wont get it in. iam sorry forgot to look at wiring sch. today at work for you, to see why it would kill the eng. yes one wire turns the fan on as soon as you turn the a/c on, to help cond keep cool. is the fan coming on when the engine cuts off, if so disconnect fan relay and see if engine keeps running when you put power to it. maybe in fan system?will look tomorrow at wiring and get back to you.

yes there is a kit costs around 16 bucks bought one to try , it came with small can of dye and a pen uv light, even brightier than my big uv, but if you have full charge the in sytem you wont get it in. iam sorry forgot to look at wiring sch. today at work for you, to see why it would kill the eng. yes one wire turns the fan on as soon as you turn the a/c on, to help cond keep cool. is the fan coming on when the engine cuts off, if so disconnect fan relay and see if engine keeps running when you put power to it. maybe in fan system?will look tomorrow at wiring and get back to you.
the switch im talking about is the low pressue switch next to the line by the accumulator...3 wires on it.. 1 black red. 1 gray,1 black..1 wire gos to the pcm..

ok are you getting any codes,maybe a code 42? i belive what is happening the engine timing is not advancing when the a/c is turned on, causing it to die. if this is the case, pull your ign control module and take it to autozone and have them check it. you will have to pull the coils off for them to check it. it sends a singnal to the a/c sends a signal to it and in turn it sends a signal to ecm request for spark and fuel advancement. i that is the only thing i can think of

ok are you getting any codes,maybe a code 42? i belive what is happening the engine timing is not advancing when the a/c is turned on, causing it to die. if this is the case, pull your ign control module and take it to autozone and have them check it. you will have to pull the coils off for them to check it. it sends a singnal to the a/c sends a signal to it and in turn it sends a signal to ecm request for spark and fuel advancement. i that is the only thing i can think of
no theres no codes come up, i had auto zone check for codes ..i put a intake gasket on this engine a few weeks ago.. mabe something come un hooked.. i know the book says the power control module gets the ground signal from the ign control module,, i know theres no kind if current to the compresser from the electrical plug, the only way i can get the compresser to come on is a hot wire from the battery..

ok check this , see if you are getting power (not jumping it out) from the low pressure switch you have one grd in, one power in and one out if you are not getting one out bad switch still would have icm checked though , pian to get the bolts out but could be it, trust me just went thru one would not start had fire , fuel and rail pressure so keep looking for something else it was it , that controls more than you could ever belive . i will look at wire diag some more today forgot and left book, and password at work for aladata. and check if grd to low pressure switch is there i belive the ecm sends a grd signal to switch not sure trying to remember . also will car run if you rev engine up when you turn a/c on forgot to ask that.

ok check this , see if you are getting power (not jumping it out) from the low pressure switch you have one grd in, one power in and one out if you are not getting one out bad switch still would have icm checked though , pian to get the bolts out but could be it, trust me just went thru one would not start had fire , fuel and rail pressure so keep looking for something else it was it , that controls more than you could ever belive . i will look at wire diag some more today forgot and left book, and password at work for aladata. and check if grd to low pressure switch is there i belive the ecm sends a grd signal to switch not sure trying to remember . also will car run if you rev engine up when you turn a/c on forgot to ask that.
i have rulled the ecm out of the picture, there is a gound from ecm to power train module.. then the ground also continues to the relay,engine coolant sensor,and the low pressure sensor.. but i get nothing from the comresser.. why wont the low pressure sensor make connection to the compresser when i jump it? it stalls the engin...im going to try to by pass the low pressure sensor and go direct to the compresser if i can..i just dont want to mess this pcm up..there is a ground at the low pressure sensor also current, when i run a hot wire from the battery to compresser the clutch kicks in, when i jump the low pressure sensor the 2 fans come on, if i jump the othe wire on the sensor it stalls the engine.. just cant get current to the compresser with out hot wire from the battery..

not the ecm but icm it is behind the coils the coils bolt to it, the low pressure sends a signal to it, and in return it sends a signal to the ecm, you can do more damage by running a straight hot wire to the comp, because you are by pass the high pressure switch, which now i think about it it could be at fault, to check it you need gauges. to see if it building up to much head pressure , also if you over charged it , it would cause the engine to die to much strain, so tell you what if you have a buddy that has some gauges hook them up and check by putting power direct to comp, not sure what the pressure switch is set for it but it should not be above 225, and that is on a hot day. if it is you have a restriction or you have over charged it, or you have blockage at the orffice tube that is simple to check. check to line before and after the orffice tube, should be close to same temp on both sides.

not the ecm but icm it is behind the coils the coils bolt to it, the low pressure sends a signal to it, and in return it sends a signal to the ecm, you can do more damage by running a straight hot wire to the comp, because you are by pass the high pressure switch, which now i think about it it could be at fault, to check it you need gauges. to see if it building up to much head pressure , also if you over charged it , it would cause the engine to die to much strain, so tell you what if you have a buddy that has some gauges hook them up and check by putting power direct to comp, not sure what the pressure switch is set for it but it should not be above 225, and that is on a hot day. if it is you have a restriction or you have over charged it, or you have blockage at the orffice tube that is simple to check. check to line before and after the orffice tube, should be close to same temp on both sides.
bt... i had the low pressure switch un pluged from the line and was juming the wires in the pigtail... so even if the switch was bad it would kick in.. i hate to take this ignition module out.. this car purs like a kitten..i know what your saying about the signals, but if it was bad the fans wouldnt come on,the ect coolant sensor thats new wouldnt read..im geting current to everthing but the compresser,, compresser relay in the fuse box reads good, the air cond,, 10amp fuse i cant get a ground from it..im boiling it down to the pcm... everything else is a ok..most of the time if the(icm) ignition modules bad you cant get a ground to the pcm.. i never fooled with the pcm i hate to take it out of there.. when i jump that pigtail with the switch unhooked both fans come on, then the comresser should kick in,, i dont know what else to do,, mabe i will take the module out and have it checked..i got 221000 on this car, so it could be a corroded wire in the pcm..

Ever find out what the problem is? I have the same issue. The low pressure sensor that you're talking about on the high side, the reason the car was dying was because you were shorting out the 5v line to ground on the PCM. The PCM effectively shut off at that point, killing the motor. If you want to short it, my guess would be gray to red. Gray is +5 Volts, black is ground and red is reading from the sensor to the pcm (at least according the the schematics). Mine shows 1 volt at the red line, which to me would be pretty low on the operability scale. However, I have no pressure in the system

QUESTION:

I haven't fully evacuated mine yet. It worked fine last year. However, I hooked up the pump and I noticed that a lot of oil was coming out of the system. Should I continue to pump it out?

Bill

Ever find out what the problem is? I have the same issue. The low pressure sensor that you're talking about on the high side, the reason the car was dying was because you were shorting out the 5v line to ground on the PCM. The PCM effectively shut off at that point, killing the motor. If you want to short it, my guess would be gray to red. Gray is +5 Volts, black is ground and red is reading from the sensor to the pcm (at least according the the schematics). Mine shows 1 volt at the red line, which to me would be pretty low on the operability scale. However, I have no pressure in the system

QUESTION:

I haven't fully evacuated mine yet. It worked fine last year. However, I hooked up the pump and I noticed that a lot of oil was coming out of the system. Should I continue to pump it out?

Bill
it was the control on the dash, i went to the bone yard and $10.00 put it on and the compresser kicked in.. if you got oil leaking you have to fix the leak.. the low pressure switch cant be jumped,, try and find out where its leaking.. the leak has to be repaired first.. then go to auto zone get r34 its $699 can with the engine runing emty the can in it,, they also have a dye that you can use to detect where its leaking.. mine wasnt leaking or low on r34 it was the control..

The control? Are you talking about the control with the knob on the left most side that has defrost, ac, floor, floor and high vents, etc?

That sounds like a tough find. How did you find it?

I don't think I have a leak. I partially evacuated it and when I did, it had pressure in it. However, when I was playing with the sensor, I had partially evacuated it. So, I'm thinking that was why I didn't have pressure.

This is kinda :banghead:

The control? Are you talking about the control with the knob on the left most side that has defrost, ac, floor, floor and high vents, etc?

That sounds like a tough find. How did you find it?

I don't think I have a leak. I partially evacuated it and when I did, it had pressure in it. However, when I was playing with the sensor, I had partially evacuated it. So, I'm thinking that was why I didn't have pressure.

This is kinda :banghead:
yes its the dash control that i needed,i checked every other thing over and over and decided to try a new control. i guess its like the head light switch i had to replace when my dash lights wouldnt work, theres a little circut board in it.. all you need to do is put a couple cans of r34 in and you should be ok.. remember turn the air on with the engine runing and it will go in real slow and ifs its real low on r34 the compresser wont kick in untill you get enough 34 in to kick that low sensor on.. its on the drivers side.. lte me know..

i did that,, if its leaking i cant find it, could the system just be totally dry, i had good air last year.. i never had it recharged since i bought it new.. is the switch at the accumulator replaceable? could it be the switch on the dash? how would i check ?

If you haven't done this already, I would recommend this site for any and all A/C questions. They have answered everyone of mine. Really good folks.

Corndog...

http://www.autoacforum.com/categories.cfm?catid=2
http://www.autoacforum.com/