Intermittently cold air will blow for a few minutes?

Hello,

If the compressor runs with refrigerant inside and does not build pressure the compressor has gone bad here is a guide to help walk you through the steps of replacing the it and recharging the system with diagrams below to show you on your truck.

https://www.2carpros.com/articles/replace-air-conditioner-compressor

and

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Check out the diagrams (Below). Please let us know what happens.

Hi Cmangum,

More than likely your high gauge is reading a very small amount of pressure but due to it being a higher pressure gauge it looks like it is not reading. If you have pressure on the low side, you will have some amount of pressure on the high side. More than likely it is pretty close to being even pressure on low and high side which basically means you compressor is not building pressure. The fact that you pulled it down and it held a vacuum shows there is no leak but the compressor itself is not building pressure. Any time the compressor is cycling but no pressure is building, it typically means the compressor is not doing anything but spinning. There is a slim chance that you have a complete restriction but that normally always presents itself as a very high pressure on the high side.

I included the procedure to replace the compressor because based on this info, that is the direction it appears to be going.

Let me know if I am missing something or didn't understand what your issue is. Thanks

https://www.2carpros.com/articles/replace-air-conditioner-compressor

AC does not work. Compressor does not engage. Shop says the relay is good. That is as far as they got. They suggested that the wire is shorted somewhere between the Low pressure switch and the relay. The shop does not have a good electrical guy so they source this type of stuff out. I decided to try myself if I can find the time. Does this sound right or should I be checking the wires replacing/testing the switch? Or looking elsewhere? Anyone know how?

This sounds like the compressor has gone out or the system is low on charge or a fuse is bad, these videos and guides can help us fix the problem with diagrams below to show you how on your car. I have included (below) the air conditioner wiring diagrams as well so you can see how the system works.

https://youtu.be/4UjfQKvrB6Y not working

and

https://youtu.be/uZrQCGwXfek recharge

and

https://youtu.be/yrhWKlQEPWw leak detection

and

https://youtu.be/4EqdrBVb0sY vacuum and recharge

and

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Let us know what happens and please upload pictures or videos of the problem.


First you have to determine why the compressor is not engaging before you will know what to look for. All AC systems have some means of disabling the compressor if the system pressure gets too low. If there is a big enough leak, the compressor could put the system into a vacuum, and that could draw in outside air. The humidity in that air combines with refrigerant to form an acid that will attack metal parts. Once the system is recharged, that moisture will circulate and freeze at the orifice tube or expansion valve. That ice will stop the flow of refrigerant until it melts. That typically causes intermittent loss of cooling that can last up to an hour.

There is a low-pressure cut-off switch or a pressure sensor that disables the compressor. The place to start is by measuring the system pressure. If it is low, you will need to search for a leak, then recover the refrigerant that is left in the system, then recharge it with the amount specified.

Ac is getting cold and working good while driving but hot when rpm's drop and idling at night. Replaced clutch on cooling fan compressor replaced. Somebody told me it could be office tube? Or somebody please tell me how to get it running right I sleep in truck at night I’m a RV transport driver.

Good afternoon,

Do you have gauges to test the high and low side pressures? I need those pressure to see if the system is working correctly.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Check the condenser in the front to be sure there is no dirt or debris in the fins. Clean them out if there is any debris.

Try spraying some water on the condenser and see if the cold air returns.

Roy

I know it’s showing high on the high side is all I was told. When they spray the condenser it got colder at idle. so they replaced the temperature blend door that fixed it.

I have auto climate control and AC will not turn on, can't get compressor clutch to engage. I have tested and replaced relay and fuses, tested low pressure switch, jumper switch. system is charged and ready. Not getting any power to the compressor. I do have issues with the ambient temperature on the mirror, it goes up while driving to about 30 or 40F higher than actual if that is in any way relevant to the situation. I've tested voltage at connection on top of compressor 0v running and not running.

Hello,

It sounds like the compressor is out the relay is not working here are two guides to help us see whats wrong and how to fix it.


https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit


Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

I found that my ambient air temp sensor had fallen and was contacting the radiator, I assume that might be why the temps were so far off. I have verified that I have plenty of refrigerant in the system and all fuses and relays are tested good. I still cannot get any voltage at the compressor. Does the BCM have anything to do with climate control, ECM

No, the PCM has control of the compressor relay. You need a scan tool that can look at data so you can see what pressure the sensor is sending to the PCM. They fail quite often and cannot be jumped out.

I pulled the hvac fuse and waited 30 seconds and then started the truck the truck. Ac came on and now working. Tip I read online someone did. I dunno. Thanks for your inputs

What you did is clear the code memory in the HVAC. Whatever code set the first time may set again and then again you may have already resolved the issue so time will tell.

Ok. So when it stared cycling, I threw my gauge on the low side port and when the compressor kicked on, the pressure dropped from 40 to about 15psi then the compressor cycled off and the pressure returned to the green zone at about 40psi.. So I replaced the relay and the problem is fixed cost me $34.00

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

when you first start the truck the A/C clutch kicks in the kicks out a few seconds later and wont come on again.

Welcome to 2CarPros.

Have you checked if it was low on Freon? If it is, this can happen. Take a look through these links and let me know if they help.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Let me know what you find or if you have other questions.

Take care,
Joe

Was blowing cold and suddenly stopped. no sign of leak, replaced the compressor relay bam! all fixed.

AC was working great, then over a period of a week or so diminished until now it just blows hot air. The compressor cycles off and on when I turn the air on, it will run for about three or four seconds, then off for about ten or twelve seconds. Over and over. Everyone says it is out of refrigerant, but I am not so sure.

Hello, I am Danny.

It sounds like you might be having a problem with the air temperature actuator. It is located on the HVAC unit under the dashboard. It is an electric motor that controls air flow through a door using different ducts. I have attached a picture (circled in red) and tutorial on how to replace. Hope this helps and feel free to ask any questions if needed. Thanks for using 2Carpros.
Danny-

https://www.2carpros.com/articles/replace-blend-door-motor

That would be a blending issue would it not? I watched the AC compressor while my wife turned it on. It will run a few seconds, then kick out for eight to ten seconds. The compressor clutch will cycle on and off like that until you turn the AC off.
There is one other issue I forgot to mention. This started about the time the AC started going out. Sometimes, especially with the fan set to high, it will just stop blowing. Several seconds later, it will come back on by itself and start blowing again. It will do that even with the AC off and just set to "blow air". Does not do it all the time though.
I hate to spend $40.00 on a can of gas just to have access to a gauge to check the gas level, but I will almost bet it is full of gas. I tend to believe it is an electrical problem. Maybe the relay for the AC? Maybe it is weak and will not hold a latch when energized, and will keep trying, but just cannot hold a latch "on". I will attempt to find the AC relay and test it. I will sure do that before buying a can of gas.
Thanks

Hello again.

Okay, I have attached a picture and circled in ted two locations to check. I have also attached a link to show how to test a relay. Hope this helps and thanks again for using 2CarPros.

Danny-

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

I checked refrigerant its good actually all they way in red (but I figured its cuz it isn't working) and I have power going to compressor clutch the blower motor still works just blows hot fuses are good and I can spin the clutch on the front of the compressor by hand but it wont spin with ac on its an expensive fix and I don't have money to get it tested and then fixed going through a rough patch with money and I live in Texas so yeah its hot and ac was prologue used a lot before I got the truck it worked.great then one day just stopped do you think you can help determine the problem. Thanks

We need to see what the high and low pressures are at. This guide can help us fix it.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please run down this guide and report back.

No it doesn't engage with ac on I thought one time when trying to find the problem the compressor made a click noise but I'm not sure if it came from that or not it just sounded ike I did if that helps but the clutch never started spinning I'm not sure about the click noise like I said.I thought it might of came from the compressor

Alright the first thing i do is check the high and low pressures when checking the ac.

How would I go about doing that I don't think I have the resources to do so I have the diy gauge you know the one from a walmart or something

You would have to get a manifold gauge set with the hoses and the high and low gauges.They even sell them at harbor frieght tools.I bought one from there a couple of years ago that iam still using till i get the money for a better set.

Ok can you give me steps of what should do and what kind of pressure should be in the hoses? And if they aren't what they aren't what they should be what would that mean I need or if they are at the right pressure what would be next step? I'm going to try and do it while at work tomorrow so I wont have Internet connection to follow up with you till after 5 I'm a golfcart mechanic so we have a lot of other tools and things where it is easy to work on my truck there

Skewed pressures could be all kinds things deoending on what they read.You said the compressor doesnt even come on so the first thing we need to do is see what the high and low pressures are?They should be even without the compresor running.Probably around 100psi also you need to pay attenion if the ac compressor comes on cycles etc?If it cycles what is the high and low pressures when the compressor turns off?Does the truck run hot?

Also make sure the manifold gauges are closed before hooking up the hoses to the truck.If there are valves on the hose ends that hook up to your truck then make sure they are turned all the way counter clock wise before hooking them to your truck.Then once there hooked up then screw them down when removing the hoses from the truck turn the valves back clock wise before removing them.

The psi is good on the lines and no the compressor doesn't kick on or cycle or anything

Alright what are the actual pressures readings high and low side?You telling me there ok doesnt tell me much.Also you said you have power to the ac clutch?I just caught that part if you do and the terminal isnt open and the power is at the terminal sounds like a bad ac compressor clutch.Also do you have auto climate control or manual ac?

Yes I have power to the clutch and its manual climate control but the lights went out on it idk if that matters it all still works if I put to floor it goes to floor and defrost still does it just the illumination lights aren't working anymore. So you know I good places to get AC compressor clutch I also heard if the clutch goes out then there's probably not much life span on the compressor left and since I live in Texas I'm wondering if you think it would be better to get both or if it matters

The way i always decide on to replace the clutch or the whole compressor is by the price difference.I would check www.rockauto.com also i copy and paste the part numbers to amazon to see which is cheaper with shipping.

Cool, thanks man I really appreciate it it has been I really hot ride and working in the heat. Blows when I can't get in a air conditioned truck

If your tight on money your best bet would be to go with just the clutch for now.Because betime you buy the compressor drier orifice tube charge etc thats a lot in parts alone.

To have to buy a new drier and all the above when I buy a new compressor? And what about a salvage yard for the clutch or would you just suggest getting a new or rebuilt clutch from that site or Amazon I looked online its going for about 180 to 200 hundred just for the clutch

Yes those are things you should change with the ac compressor and have to replace to get a warranty on the new compressor.What size engine do you have?

Also do you have the denso compressor?