AC Compressor cycles on and off every 5 seconds - Help
#1
AC Compressor cycles on and off every 5 seconds - Help
Hello,
nOOB here to the forum and to Honda's in general. Thanks for the great forum. I just bought a 2000 civic ex and it has following problem.
The AC compressor will cycle on and off every 5 seconds or so. The condensing fan motor runs constantly.
The low side pressure is 120 and the high side pressure is 120 as well, this is with the car on and off. I don't see any difference in the pressures during the short time the compressor is on.
I feel the clutch is working because there is an RPM drop during the 5 seconds or so the compressor comes on.
I've read that I need to jumper out the pressure switch, assuming that is good what else should I be looking at?
Thanks for the input.
Casey
nOOB here to the forum and to Honda's in general. Thanks for the great forum. I just bought a 2000 civic ex and it has following problem.
The AC compressor will cycle on and off every 5 seconds or so. The condensing fan motor runs constantly.
The low side pressure is 120 and the high side pressure is 120 as well, this is with the car on and off. I don't see any difference in the pressures during the short time the compressor is on.
I feel the clutch is working because there is an RPM drop during the 5 seconds or so the compressor comes on.
I've read that I need to jumper out the pressure switch, assuming that is good what else should I be looking at?
Thanks for the input.
Casey
#2
Re: AC Compressor cycles on and off every 5 seconds - Help
What is the ambient air temperature at the time?
What is the temperature of the vehicle? Are these pressures when the vehicle is cold?
You say the compressor clutch engages. ( you shold be able to watch the clutch on the compressor cycle on and off making the compressor shaft spin ). The condensor fan works. You say 120 psi static and when compressor is on.
I would start by removing all refrigerant and recharging to manufacturers specifications. System charge and oil content is critical for proper operation.
I would recheck the system and decide what to do next.
That's what I would do.
What is the temperature of the vehicle? Are these pressures when the vehicle is cold?
You say the compressor clutch engages. ( you shold be able to watch the clutch on the compressor cycle on and off making the compressor shaft spin ). The condensor fan works. You say 120 psi static and when compressor is on.
I would start by removing all refrigerant and recharging to manufacturers specifications. System charge and oil content is critical for proper operation.
I would recheck the system and decide what to do next.
That's what I would do.
#4
Re: AC Compressor cycles on and off every 5 seconds - Help
What is the ambient air temperature at the time?
It was about 95
What is the temperature of the vehicle? Are these pressures when the vehicle is cold?
The pressures were taken when the car was hot
You say the compressor clutch engages. ( you shold be able to watch the clutch on the compressor cycle on and off making the compressor shaft spin ). The condensor fan works. You say 120 psi static and when compressor is on.
I'm assuming the compressor is coming on because of the lag in RPM and I confirmed 12v going to the AC clutch. I'll look to make sure the shaft is spinning as well
Yes, I have 120 low and 120 high when the vehicle is off and when the AC is on.....Would I be able to see a pressure change given the short periods of time the compressor is on?
I would start by removing all refrigerant and recharging to manufacturers specifications. System charge and oil content is critical for proper operation.
OK, I'll remove refrigerant and recharge
I would recheck the system and decide what to do next.
That's what I would do.
It was about 95
What is the temperature of the vehicle? Are these pressures when the vehicle is cold?
The pressures were taken when the car was hot
You say the compressor clutch engages. ( you shold be able to watch the clutch on the compressor cycle on and off making the compressor shaft spin ). The condensor fan works. You say 120 psi static and when compressor is on.
I'm assuming the compressor is coming on because of the lag in RPM and I confirmed 12v going to the AC clutch. I'll look to make sure the shaft is spinning as well
Yes, I have 120 low and 120 high when the vehicle is off and when the AC is on.....Would I be able to see a pressure change given the short periods of time the compressor is on?
I would start by removing all refrigerant and recharging to manufacturers specifications. System charge and oil content is critical for proper operation.
OK, I'll remove refrigerant and recharge
I would recheck the system and decide what to do next.
That's what I would do.
Thanks again,
Casey
#5
Honda-Tech Member
Re: AC Compressor cycles on and off every 5 seconds - Help
NOTE: Remember to PURGE the line going from your Refrigerant bottle to your Low Side port or you will likely put Air in the system. I have 30lb bottles I use so once I get the bottle hooked up to the Gauge Manifold. I open the Valve on the Bottle and then where the line going from the Bottle to the Gauge Manifold connects, I unscrew that to purge the air out of the line. Then I open the Low Side valve on the Manifold to start charging the system with Refrigerant.
#6
Re: AC Compressor cycles on and off every 5 seconds - Help
You will NOT have to jump the Pressure Switch when Re-Charging with Refrigerant. Start the car and turn the A/C wide open. Since there is no Refrigerant in the system the Compressor won't actually come on due to the Low Pressure switch keeping it shut off. Once you start charging and get a certain amount of Refrigerant into the system then the Compressor will automatically cut on which you will notice by the Clutch Engaging.
NOTE: Remember to PURGE the line going from your Refrigerant bottle to your Low Side port or you will likely put Air in the system. I have 30lb bottles I use so once I get the bottle hooked up to the Gauge Manifold. I open the Valve on the Bottle and then where the line going from the Bottle to the Gauge Manifold connects, I unscrew that to purge the air out of the line. Then I open the Low Side valve on the Manifold to start charging the system with Refrigerant.
NOTE: Remember to PURGE the line going from your Refrigerant bottle to your Low Side port or you will likely put Air in the system. I have 30lb bottles I use so once I get the bottle hooked up to the Gauge Manifold. I open the Valve on the Bottle and then where the line going from the Bottle to the Gauge Manifold connects, I unscrew that to purge the air out of the line. Then I open the Low Side valve on the Manifold to start charging the system with Refrigerant.
#7
Re: AC Compressor cycles on and off every 5 seconds - Help
At 95 degrees F, those pressure sound about right. Either the compressor is not engaging or the expansion valve is stuck wide open. Though, I have not seen low side pressures stay that high ( matching the high side and not moving at all ) with a stuck open expansion valve. There is still some restriction when it's open all the way.
I would confirm that the compressor clutch is engaging and the compressor shaft is spinning.
I would confirm that the compressor clutch is engaging and the compressor shaft is spinning.
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#8
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Re: AC Compressor cycles on and off every 5 seconds - Help
mine did the exact same thing. on top of the hood area above the condencer area, there is a ground wire. check that. i fixed that and good as new!!
#10
Re: AC Compressor cycles on and off every 5 seconds - Help
Thanks for all the responses guys. I'll confrim the shaft is spinning on the compressor and report back.
Thanks again,
Casey
ETA: Assuming the shaft is spinning, is there a way to confirm the compressor is actually working? I mean it sounds like if I have equal pressure that it could be the compressor or the expansion valve. Obviously I'd start with the expansion valve as it's cheaper but it would be nice to know if there is a sure shot way of testing the compressor. I'd hate to change the expansion valve, re-charge and then finding out it's the compressor.
Thanks guys,
Thanks again,
Casey
ETA: Assuming the shaft is spinning, is there a way to confirm the compressor is actually working? I mean it sounds like if I have equal pressure that it could be the compressor or the expansion valve. Obviously I'd start with the expansion valve as it's cheaper but it would be nice to know if there is a sure shot way of testing the compressor. I'd hate to change the expansion valve, re-charge and then finding out it's the compressor.
Thanks guys,
Last edited by Rooftop-Special; 06-01-2010 at 07:52 PM.
#11
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Re: AC Compressor cycles on and off every 5 seconds - Help
Hello, I hope the OP doesn't mind that I ask a question on this thread, I'm having similar problems in my 99 Civic Si, and would like to get some help to resolve it.
The other day, I noticed that my A/C stopped blowing cold air. Popped the hood, and noticed the Compressor Clutch wouldn't click on. Checked the fuses and sure enough, the Fuse to the Condenser Fan was busted. The condenser was busted so me and my father replaced it, no more busted fuses and A/C was back to blowing cool air.
My Father insisted that I recharge the system with freon. He used an autozone bought pressure gauge with the freon, and used about a can and a half. Air was slightly colder not by much, but I started noticing the Clutch on the compressor would cycle on and off every few seconds or so.
What I heard/read was that this was a symptom of an overcharged system. What I'd like to do is get the whole system evacuated and recharged. Is this possible to do at home or would it need to go to a shop? I'm reluctant to press the A/C button until this is resolved in fear of blowing out the Compressor, which is really expensive!
Houston Heat is ridiculous and any information and help is greatly appreciated
The other day, I noticed that my A/C stopped blowing cold air. Popped the hood, and noticed the Compressor Clutch wouldn't click on. Checked the fuses and sure enough, the Fuse to the Condenser Fan was busted. The condenser was busted so me and my father replaced it, no more busted fuses and A/C was back to blowing cool air.
My Father insisted that I recharge the system with freon. He used an autozone bought pressure gauge with the freon, and used about a can and a half. Air was slightly colder not by much, but I started noticing the Clutch on the compressor would cycle on and off every few seconds or so.
What I heard/read was that this was a symptom of an overcharged system. What I'd like to do is get the whole system evacuated and recharged. Is this possible to do at home or would it need to go to a shop? I'm reluctant to press the A/C button until this is resolved in fear of blowing out the Compressor, which is really expensive!
Houston Heat is ridiculous and any information and help is greatly appreciated
#12
Re: AC Compressor cycles on and off every 5 seconds - Help
^^ Very true. Sometimes the compressor clicks on and off when the freon level is a little too high.
Dad insisted that I recharge the system with freon
#13
Re: AC Compressor cycles on and off every 5 seconds - Help
Not to thread jack as well, but when my A/C is on, it makes the car idle to the very lowest point and it's done it since I've had the car. Gave it a charge about a month ago. And I have no clue how to examine an A/C. I know what the compressor is but doesn't know how it functions, when the fan should and shouldn't engage and same to the clutch.
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