AC works great at night,early morning. But in the day time when its hot it stops
AC works great at night,early morning. But in the day time when its hot it stops
Hi. I own a almost mint 1990 240sx with 122,000 miles. Currently its charged with 12 refrigerant. Ive been having a strange problem with my AC. Air works great at night or early morning but in the day time when its hot stops working. I have a full charge. Any one else with this same problem???? Thanks, D
Re: AC works great at night,early morning. But in the day time when ... (mrneg9)
is the compessor clutch engaging?
in the heat i have noticed it takes a little longer to get nice and cold in my car. im running r12 also
in the heat i have noticed it takes a little longer to get nice and cold in my car. im running r12 also
Re: AC works great at night,early morning. But in t ... (danielsan)
I have popped the hood and looked and no the compressor clutch stops moving. Im wondering what causes it to shut off only when its real hot out ???
Re: AC works great at night,early morning. But in the day time when ... (mrneg9)
maybe its something with the relay.
Re: AC works great at night,early morning. But in t UPDATE
Well today I checked over a couple of things. Seems if I unplug the two plugs on the condenser fan my ac clutch stays engaged and runs fine. When the fan is plugged in I think its over heating the relay and shutting the compressor clutch down. Why does the fan have two plugs going to it and if I run the car with out the condenser fan running will it make a difference?
Re: AC works great at night,early morning. But in t UPDATE (mrneg9)
When the ac shuts off during the day, look at the AC fan. Is it running? If not then the AC will shut off because it has a temperature safety switch.
If it's not running and you just unplug the fan then, perhaps you're just bypassing the fan and making it work.
If it's not running and you just unplug the fan then, perhaps you're just bypassing the fan and making it work.
Re: AC works great at night,early morning. But in t UPDATE (240FeVeR)
The ac works fine as long as the fan is unplugged. After you plug in the two connectors to the fan the AC will only work for a short time before it heats up the AC relay and shuts the compressor clutch down. I know this because if you put the relay in the freezer for a bit and plug it back in the AC goes right on and runs. I thought maybe it was the relay but I replaced it and still the same thing. I even went and eliminated the temp. control switch and wired the fan up so it would come on all the time when the air is turned on but still it ends up heating the relay up and shutting the ac compressor down. Could the fan motor be bad? The next thing I'm going to do is wire a switch in side the car so that the fan is not running of that dam relay. Some one out there has had to have been down this road ? Keep the suggestions going. Thanks.
Re: AC works great at night,early morning. But in t UPDATE (mrneg9)
Well Ive tried it all. The AC works fine until it gets hot outside then the ac clutch shuts down. What a pain in the ***. Used it today and it worked even when it was hot. As soon as I shut the air off and tried to turn it back on the clutch would not engage. Then later tonight when it cooled down it works again. What a pain in the ***.
Re: AC works great at night,early morning. But in the day time when ... (mrneg9)
To me it sounds like you need to start by adding a can of Freon to the system. I would NOT want the compressor to cycle during this time….or the system is still low. If the compressor cycles too quickly you could have a restriction like an orifice tube that is clogged.
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misafasheti
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Re: AC works great at night,early morning. But in the day ti
I'm sure that the original user of this thread already resolved the issue but here is what I think the answer is:
My 1993.5 G20 works very well in the morning, late evening, and at night. No issues there. But...during the middle of the day (Tucson AZ summers) the compressor will just stop working. At first the temperature gauge on my dashboard wasn't working but once I got it working I noticed that my car is running hot during the day, and that this is tied directly to your car AC. When the temperature needle on my instrument panel gets above halfway (up to halfway is probably normal operating termperature) then the the AC compressor shuts off and I feel warm air almost immediately. This happens more in stop-and-go traffic. Once I start to go down the road for a little while and I notice that the temperature needle moves at or below the halfway point then the AC compressor kicks back on and I can feel the super cold air again (relief!). I did some research and learned that car AC compressors have a temperature safety switch (might not be called that on all cars) that shuts the compressor down when the engine gets too hot in order to prevent self-destruction.
So my diagnosis is...faulty car cooling system. There are several things that I am going to try, as my car is old. I am first going to replace the radiator cap and the thermostat. Might as well do a coolant flush while I'm at it (all inexpensive repairs). And first and foremost make sure your car has enought coolant for the car! If that doesn't work to keep the engine below operating temperature then I'm going to pull the radiator out and have it pressure and flow tested. If it passes then at that point I wont know what else to do other than replace the radiator. A leaking water pump could also cause the issue. Another issue could be the fans on the radiator. The fans on my car have two speeds. When the car gets really hot the high speed kicks in ( I have seen it). If the fans are not spinning at their proper speed and thus not keeping the car cool enough then this could be the culprit to the overheating issue.
In short, the problem isnt with the AC, its with the car coolant system. The AC doesn't work during the day when it's hottest in order to preserve itself and the car engine. Make sure the car is functioning at normal operating termperatures.
My 1993.5 G20 works very well in the morning, late evening, and at night. No issues there. But...during the middle of the day (Tucson AZ summers) the compressor will just stop working. At first the temperature gauge on my dashboard wasn't working but once I got it working I noticed that my car is running hot during the day, and that this is tied directly to your car AC. When the temperature needle on my instrument panel gets above halfway (up to halfway is probably normal operating termperature) then the the AC compressor shuts off and I feel warm air almost immediately. This happens more in stop-and-go traffic. Once I start to go down the road for a little while and I notice that the temperature needle moves at or below the halfway point then the AC compressor kicks back on and I can feel the super cold air again (relief!). I did some research and learned that car AC compressors have a temperature safety switch (might not be called that on all cars) that shuts the compressor down when the engine gets too hot in order to prevent self-destruction.
So my diagnosis is...faulty car cooling system. There are several things that I am going to try, as my car is old. I am first going to replace the radiator cap and the thermostat. Might as well do a coolant flush while I'm at it (all inexpensive repairs). And first and foremost make sure your car has enought coolant for the car! If that doesn't work to keep the engine below operating temperature then I'm going to pull the radiator out and have it pressure and flow tested. If it passes then at that point I wont know what else to do other than replace the radiator. A leaking water pump could also cause the issue. Another issue could be the fans on the radiator. The fans on my car have two speeds. When the car gets really hot the high speed kicks in ( I have seen it). If the fans are not spinning at their proper speed and thus not keeping the car cool enough then this could be the culprit to the overheating issue.
In short, the problem isnt with the AC, its with the car coolant system. The AC doesn't work during the day when it's hottest in order to preserve itself and the car engine. Make sure the car is functioning at normal operating termperatures.
Re: AC works great at night,early morning. But in the day ti
this ^^khooper wrote:To me it sounds like you need to start by adding a can of Freon to the system. I would NOT want the compressor to cycle during this time….or the system is still low. If the compressor cycles too quickly you could have a restriction like an orifice tube that is clogged.
the system is probably low on gas,
The higher duty cycle and reduced cooling efficiency of the condenser is combining with the low gas concentration, causing the compressor to cycle off for safety. (imo)
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98blackbell
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Re: AC works great at night,early morning. But in the day ti
Seen this happen on my son's car with the temp of car going up and the a/c not working as efficient.
Normal driving with a/c off and the water temps stay between 158 and 168. This is on a AEM water temp digital/analog gauge.
When a/c is turned on and running in traffic stop and go the water temp will got to 180 to 190. Little to no change in the cars stock gauge.
I have 2 electric fans on the inside of the aluminum rad. They pull air thru the rad. I do not have the auxiliary fan on the a/c rad. I was thinking of adding this but was worried about the push/pull effect of the 2 fans.
Any ideas?
I set the fans to come on at ignition on and would like for them to go back to temp on only and run after the car is turned off.
Normal driving with a/c off and the water temps stay between 158 and 168. This is on a AEM water temp digital/analog gauge.
When a/c is turned on and running in traffic stop and go the water temp will got to 180 to 190. Little to no change in the cars stock gauge.
I have 2 electric fans on the inside of the aluminum rad. They pull air thru the rad. I do not have the auxiliary fan on the a/c rad. I was thinking of adding this but was worried about the push/pull effect of the 2 fans.
Any ideas?
I set the fans to come on at ignition on and would like for them to go back to temp on only and run after the car is turned off.
Re: AC works great at night,early morning. But in the day ti
I've been having the same problem with one of my cars, I'll probably go get some freon today. Hope that takes care of the problem.
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Wc240
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Re: AC works great at night,early morning. But in the day ti
could be a clogged condensor(in front of the radiator, not allowing airflow)
could be low. system(i believe) has a HIGH pressure cut off. if it gets too hot, pressure goes up to high
imo, id look to a plugged condensor/radiator fins, to start
could be low. system(i believe) has a HIGH pressure cut off. if it gets too hot, pressure goes up to high
imo, id look to a plugged condensor/radiator fins, to start
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TheRealNap0le0n
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Re: AC works great at night,early morning. But in the day ti
negative... the system is overcharged....kingtal0n wrote:this ^^khooper wrote:To me it sounds like you need to start by adding a can of Freon to the system. I would NOT want the compressor to cycle during this time….or the system is still low. If the compressor cycles too quickly you could have a restriction like an orifice tube that is clogged.
the system is probably low on gas,
The higher duty cycle and reduced cooling efficiency of the condenser is combining with the low gas concentration, causing the compressor to cycle off for safety. (imo)
if it works when it is cool out and not when it is hot its because the system is slightly over charged and when its cool out it comes into correct operating psi but when its hot out the gas naturally expands a bit more in the system thus tripping the high pressure sensor.
btw good luck finding R12 anywhere
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misafasheti
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Re: AC works great at night,early morning. But in the day ti
Repair update: Ok, so I replaced the thermostat (I think it was the original one with 190K miles), did a radiator flush (didn't know you have to bleed air from the engine after a radiator flush btw), replaced the cap. It worked better but still did not fix the problem:compressor still turned off during the hottest part of the day. Took it to a friends house and he put the gauges on during this super hot part of the day. He said that the pressures were way too high and suspected that the system was overcharged. Took some gas out (luckily, the 1993.5 version of this car is the first year that they started using R134), still didn't fix the issue.
So, check this out...he sprays the front of the condensor\radiator with a hose (not too much pressure as to not bend the fins) and walaa! Pressures go down on the gauges. So...I did a more thorough job and between the condensor and radiator there were cloges of dirt! I sprayed everything down (gently) and the system works great now. I have to have it on full blast during the day but the AC compressor is cycling on and off now and cold air is always blowing. What a simple fix! I'm grateful.
So, check this out...he sprays the front of the condensor\radiator with a hose (not too much pressure as to not bend the fins) and walaa! Pressures go down on the gauges. So...I did a more thorough job and between the condensor and radiator there were cloges of dirt! I sprayed everything down (gently) and the system works great now. I have to have it on full blast during the day but the AC compressor is cycling on and off now and cold air is always blowing. What a simple fix! I'm grateful.
Re: AC works great at night,early morning. But in the day ti
I am having the same problem. Please explain to me in dumb blonde girl non-car person terms what you did to repair this. I want to be able to talk to my mechanic and pretend I know what I am talking about. Many thanks.