"Air conditioning" 120deg at vent
07-24-2018, 06:25 PM
#1
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"Air conditioning" 120deg at vent
The AC in this 98 i30 was -fine- not two weeks ago...I was getting 42deg on the freeway during my Inspection adventure. It does work better when the Auto control isn't set lower than 70 (when the auto fan is running "three blades" or fewer).
It has been hella hot recently and I was thinking about putting guages on it re: recent complaints operating performance - but today is something else. Today and recently the complaint has been "a/c no workee". I didn't see any issue the last time I investigated - but today the air coming out of the vent sure is every bit of 120deg...when it's only 99 degrees outside = I suspect air from the heater core is making its way into the cabin at all or most times.
When I adjust the Auto temp up to 80+, the Auto fan drops down to "one blade" i.e. it can tell what temp is in the cabin. In Auto @ 70 deg, both cooling fans click on, and the Compressor clutch engages. Move to "econo" and the fans go off, and AC clutch disengages = Normal Operation.
Temp values from an analog dial probe stuck in the middle vent.
What to do / where to start?
It has been hella hot recently and I was thinking about putting guages on it re: recent complaints operating performance - but today is something else. Today and recently the complaint has been "a/c no workee". I didn't see any issue the last time I investigated - but today the air coming out of the vent sure is every bit of 120deg...when it's only 99 degrees outside = I suspect air from the heater core is making its way into the cabin at all or most times.
When I adjust the Auto temp up to 80+, the Auto fan drops down to "one blade" i.e. it can tell what temp is in the cabin. In Auto @ 70 deg, both cooling fans click on, and the Compressor clutch engages. Move to "econo" and the fans go off, and AC clutch disengages = Normal Operation.
Temp values from an analog dial probe stuck in the middle vent.
What to do / where to start?
07-24-2018, 09:55 PM
#4
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It says 38 and 39, thats:
38 - 20% Fre
39 - REC
It also reported 25 Sun Load Sensor but I was indoors at night. I did not actually start the engine.
I couldn't make it advance to 52 (maybe bc not running or doing it wrong).
38 - 20% Fre
39 - REC
It also reported 25 Sun Load Sensor but I was indoors at night. I did not actually start the engine.
I couldn't make it advance to 52 (maybe bc not running or doing it wrong).
Last edited by reallywildstuff; 07-24-2018 at 10:09 PM.
07-25-2018, 10:16 AM
#5
Don't worry about code 25
Don't worry about code 52, half of us can't get it to advance to 52 either
My old thread may help you a little with pictures and more info.
https://maxima.org/forums/4th-genera...out-vents.html
07-25-2018, 10:41 AM
#6
You have to have the engine running for steps 4 & 5 of the test to run/run properly.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
07-25-2018, 10:53 AM
#7
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Mithrandir:
do your words "intake door motor" =
words on that link "Air/Blend Door Motor: 277322L901" =
infinitiparts deal "Actuator Assy-Air Mix 27732-2L900, replaced by 27732-2L901 "?
https://www.infinitipartsdeal.com/pa...70_B001,27733N
do your words "intake door motor" =
words on that link "Air/Blend Door Motor: 277322L901" =
infinitiparts deal "Actuator Assy-Air Mix 27732-2L900, replaced by 27732-2L901 "?
https://www.infinitipartsdeal.com/pa...70_B001,27733N
07-25-2018, 10:58 AM
#8
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do you think I should replace the air mix door and test again, or:
replace the Fresh Vent motor at the same time I've got the ECU out (which looks like a _really_ awesome time).
replace the Fresh Vent motor at the same time I've got the ECU out (which looks like a _really_ awesome time).
You have to have the engine running for steps 4 & 5 of the test to run/run properly.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
07-26-2018, 11:04 AM
#9
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I did this below. I think the air mix door is working as designed - I increased and decreased the temp on the control panel and observed the white cam moving back and forth. I also looked up underneath the center binnacle and actually observed what I think is the door proper opening and closing.
So...I'm not getting any cold air, I got those codes 38 & 39, but the air mix door looks good. In the video you can hear me say "the temp is coming down" followed by "the a/c (the compressor) clicking on". I haven't put gauges on it yet BUT doesn't this have a low pressure switch that would prohibit the clutch from engaging without refrigerant in it ?
So...I'm not getting any cold air, I got those codes 38 & 39, but the air mix door looks good. In the video you can hear me say "the temp is coming down" followed by "the a/c (the compressor) clicking on". I haven't put gauges on it yet BUT doesn't this have a low pressure switch that would prohibit the clutch from engaging without refrigerant in it ?
You have to have the engine running for steps 4 & 5 of the test to run/run properly.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
Errors 38 and 39 are for the cabin air recirculate motor. Assuming that those errors are legitimate, they would not be the cause of your hot air problem. I would think the air mix door motor is doing this.
You can visually see if the air mix door motor is working. In the passenger side footwell, remove the trim cover from the end of the ECU. Then with the ignition key turned on (the engine does not have to be running), press the temperature up/down button and watch the arm on the air mix door motor. It should move if everything is OK. If it doesn't, you could have a bad motor or the control panel is bad. Follow the appropriate diagnostic procedure.
07-26-2018, 08:44 PM
#10
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"How do I access the Intake door / motor?"
I pulled out my gauge set. Can't get the low side Quick Disconnect to seal (on either the Nissan or the Chevy). I am starting to suspect that the Nissan system is somehow discharged (even though the clutch is engaging) - and not just because of my leaky tool...although the AC really was working SO well not a month ago, I guess a leak can occur at any time. Will fix the gauge set tomorrow and try again.
I ran the tests again with the engine running. 25, 38, and 39, again.
I don't see a troubleshooting flowchart for any 30-series "Intake Door" codes (different than the Mix door in the video above) in the FSM. It instead talks about looking at the Intake Door (above the glove box?) operation while cycling thru the 40-series codes. All of the 40 series Temps/Modes seemed to match what the FSM described - except for the "Cold" part.
There was definitely a difference between whats supposed to be "hot" (110 deg+) and "cold" (80 deg when I first started tonight, 90 deg once the car was hot); the 80-90deg "Cold" is why I think the system is discharged / low on refrigerant (again, even though the clutch is activating).
I don't understand how the results of the 40-series tests inform the 38 and 39 codes - unless it's only by visually checking the intake Door operation.
"How do I access the Intake door / motor?"
I pulled out my gauge set. Can't get the low side Quick Disconnect to seal (on either the Nissan or the Chevy). I am starting to suspect that the Nissan system is somehow discharged (even though the clutch is engaging) - and not just because of my leaky tool...although the AC really was working SO well not a month ago, I guess a leak can occur at any time. Will fix the gauge set tomorrow and try again.
I ran the tests again with the engine running. 25, 38, and 39, again.
I don't see a troubleshooting flowchart for any 30-series "Intake Door" codes (different than the Mix door in the video above) in the FSM. It instead talks about looking at the Intake Door (above the glove box?) operation while cycling thru the 40-series codes. All of the 40 series Temps/Modes seemed to match what the FSM described - except for the "Cold" part.
There was definitely a difference between whats supposed to be "hot" (110 deg+) and "cold" (80 deg when I first started tonight, 90 deg once the car was hot); the 80-90deg "Cold" is why I think the system is discharged / low on refrigerant (again, even though the clutch is activating).
I don't understand how the results of the 40-series tests inform the 38 and 39 codes - unless it's only by visually checking the intake Door operation.
"How do I access the Intake door / motor?"
Last edited by reallywildstuff; 07-27-2018 at 08:44 AM.
07-27-2018, 09:40 AM
#11
I don't understand the inner workings of the self diagnostic. To me it doesn't seem to have a definite error number/code for the air mix door motor, which is why I do a visual inspection.
But the video shows that the air mix door motor is working, so that is not your problem. Ditto for the intake door motor.
Checking the charge in the a/c system is the next step.
But the video shows that the air mix door motor is working, so that is not your problem. Ditto for the intake door motor.
Checking the charge in the a/c system is the next step.
07-27-2018, 10:26 AM
#12
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07-27-2018, 08:44 PM
#13
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I fixed my gauge set (o-Ring in the low side coupler).
83 psi both sides at rest
Running, Auto, set to 67
Friday night in Houston TX (85deg)
low: 60 psi
hi: 100 psi
temp at vent: 78 deg
never gets any higher/lower and compressor never cycles
That's "not enough refrigerant". I have an electronic leak detector but it is helpfully not working. I also have a vacuum pump.
what to do next? At purchase 7 years ago the low side Schrader valve was leaking and was replaced by a shop (that I really liked, that is helpfully out of business). No AC service was done since. Yesterday when I took the low side cap off (prob first time in 7 years) there was yellow dye under the cap. I wonder if it is leaking again at that location - or if it was just never cleaned. I never investigated before this round of fix it (never looked).
83 psi both sides at rest
Running, Auto, set to 67
Friday night in Houston TX (85deg)
low: 60 psi
hi: 100 psi
temp at vent: 78 deg
never gets any higher/lower and compressor never cycles
That's "not enough refrigerant". I have an electronic leak detector but it is helpfully not working. I also have a vacuum pump.
what to do next? At purchase 7 years ago the low side Schrader valve was leaking and was replaced by a shop (that I really liked, that is helpfully out of business). No AC service was done since. Yesterday when I took the low side cap off (prob first time in 7 years) there was yellow dye under the cap. I wonder if it is leaking again at that location - or if it was just never cleaned. I never investigated before this round of fix it (never looked).
Last edited by reallywildstuff; 07-27-2018 at 09:10 PM.
07-28-2018, 01:21 PM
#14
I fixed my gauge set (o-Ring in the low side coupler).
83 psi both sides at rest
Running, Auto, set to 67
Friday night in Houston TX (85deg)
low: 60 psi
hi: 100 psi
temp at vent: 78 deg
never gets any higher/lower and compressor never cycles
That's "not enough refrigerant". I have an electronic leak detector but it is helpfully not working. I also have a vacuum pump.
what to do next? At purchase 7 years ago the low side Schrader valve was leaking and was replaced by a shop (that I really liked, that is helpfully out of business). No AC service was done since. Yesterday when I took the low side cap off (prob first time in 7 years) there was yellow dye under the cap. I wonder if it is leaking again at that location - or if it was just never cleaned. I never investigated before this round of fix it (never looked).
83 psi both sides at rest
Running, Auto, set to 67
Friday night in Houston TX (85deg)
low: 60 psi
hi: 100 psi
temp at vent: 78 deg
never gets any higher/lower and compressor never cycles
That's "not enough refrigerant". I have an electronic leak detector but it is helpfully not working. I also have a vacuum pump.
what to do next? At purchase 7 years ago the low side Schrader valve was leaking and was replaced by a shop (that I really liked, that is helpfully out of business). No AC service was done since. Yesterday when I took the low side cap off (prob first time in 7 years) there was yellow dye under the cap. I wonder if it is leaking again at that location - or if it was just never cleaned. I never investigated before this round of fix it (never looked).
07-28-2018, 05:37 PM
#15
07-30-2018, 05:16 AM
#16
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Posts: 615
My initial reported symptoms match "air mix door" problems, and Olorin helpfully pointed out his own mix door experiences in reponse.
Investigation reveals my own mix door seems to function "OK". I have yet to determine why the computer is instead reporting problems with the Intake door on my car.
Assuming I can fix up the charge in the A/C - I wonder how the system temperature will perform / spec out with the Intake door showing those problems.
07-30-2018, 06:26 AM
#17
As long as the control panel in the dash is sending the run signal to the a/c compressor, the compressor will run as long as the charge is OK. The various motors under the dash control the direction of the air in the ducts.
The air intake door motor controls where the air that enters the duct system to be heated/cooled comes from, either outside air or from within the passenger cabin, i.e., recirculate. The airflow is then routed to the a/c evaporator coil.
The air mix door motor is the only one that affects the temperature of the air blowing into the passenger cabin by routing the airflow coming out of the evaporator coil through the heater core, which would then warm the air back up or routing the air around the heater core to leave it at whatever the air temperature is. The various temperature sensors tell the control panel whether to move the air mix door. The self diagnostic tests these temperature sensors during step 2. As your video shows, this motor is working.
The mode door motor then directs the air so it will blow out the vents you have selected, the floor, the dash or the defrost.
For the air intake error codes, you will have to do a visual check to see if they are real. I'm going to assume that they probably are. You will need to remove the glove box as the motor is located above this. And similar what you did for the air mix motor, watch the arm on the motor and see if it moves when you press the recirculate button on the control panel.
I think that your hot air problem is with the compressor/refrigerant part of the a/c system.
The air intake door motor controls where the air that enters the duct system to be heated/cooled comes from, either outside air or from within the passenger cabin, i.e., recirculate. The airflow is then routed to the a/c evaporator coil.
The air mix door motor is the only one that affects the temperature of the air blowing into the passenger cabin by routing the airflow coming out of the evaporator coil through the heater core, which would then warm the air back up or routing the air around the heater core to leave it at whatever the air temperature is. The various temperature sensors tell the control panel whether to move the air mix door. The self diagnostic tests these temperature sensors during step 2. As your video shows, this motor is working.
The mode door motor then directs the air so it will blow out the vents you have selected, the floor, the dash or the defrost.
For the air intake error codes, you will have to do a visual check to see if they are real. I'm going to assume that they probably are. You will need to remove the glove box as the motor is located above this. And similar what you did for the air mix motor, watch the arm on the motor and see if it moves when you press the recirculate button on the control panel.
I think that your hot air problem is with the compressor/refrigerant part of the a/c system.
08-12-2018, 11:13 AM
#18
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Yeah there's a tool that out there to allow you change a schrader valve without discharging the entire system...
https://www.youtube.com/watch?v=A3eLrWP70uE
https://www.youtube.com/watch?v=A3eLrWP70uE
I can successfully use the tool to unthread (and, as it turns out, also re-thread) the valve from the port - but the loose valve is NOT making it past the tools' ball valve.
Sometimes the plunger, still engaged with the loose valve, will "get stuck" in the ball valve and not fully retract. When this happens the valve is wedged in the ball - creating a near-complete seal - and preventing the ball valve handle from turning.
Sometimes the tool will disengage from the loose valve, and the plunger will fully retract under pressure from within - but when the ball valve is turned and the plunger removed, SURPRISE the valve is still loose in the pressurized part of the tool.
Meanwhile - test the tool w a new valve on the bench: and the valve will slide back and forth past the tools' ball valve all day long.
So - so much for that plan. But I'll try again later - especially if someone here has got any good ideas that'll help.
08-18-2018, 01:26 PM
#21
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I had the AC professionally serviced. Although it was indeed low on refrigerant (having leaked thru the low side valve, which has now been replaced) the shop's diagnosis is "weak compressor" i.e. the clutch cycles but the pressure barely rises at all. CURSES.
It reportedly has the requisite 1.4 lbs in it now but it is "not cooling even a little bit". I am waiting on a replacement coupler for my own gauge set (part of the reason I farmed out the work) so I haven't seen the pressures myself. Presumably they would not be that much different than what I reported previously.
I am super bummed about this revolting development. I can't yet bring myself to even look up what all those necessary replacement parts would cost. The shop didn't even prepare a quote for me because they know me so well (knew I wouldnt want them to do it) but they are going to give me one when they open on Monday.
It reportedly has the requisite 1.4 lbs in it now but it is "not cooling even a little bit". I am waiting on a replacement coupler for my own gauge set (part of the reason I farmed out the work) so I haven't seen the pressures myself. Presumably they would not be that much different than what I reported previously.
I am super bummed about this revolting development. I can't yet bring myself to even look up what all those necessary replacement parts would cost. The shop didn't even prepare a quote for me because they know me so well (knew I wouldnt want them to do it) but they are going to give me one when they open on Monday.
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