Vehicle AC System Diagnosis for Beginners. A/C System Troubleshooting
In this video I’m going to show you the steps that you can take to diagnose an AC system that does not blow cold. The first thing you you should verify is, does the compressor turn on. If the A/C compressor does not turn on, then the vehicle is never going to get cold. There are multiple things that could keep a compressor from turning on: no refrigerant, electrical problems, or a mechanical problem with the clutch.
If your clutch engages I will also show you how to diagnose problems with your AC system using a manifold gauge set. I will show you the correct way to connect manifold gauge set to your vehicle. Once the gauges are connected to your high and low side pressure ports I will help you interpret the gauge readings to help you find out what is wrong with your vehicle’s air conditioner.
Links to other AC videos I’ve done:
How to find refrigerant leaks: https://youtu.be/4NnIarJjXUk
Compressor Clutch Replacement: https://youtu.be/fe_y7kgM4Rk?si=VBUKphcV-0_yXqMC
AC System Flushing: https://youtu.be/N_msH6TX2W4?si=xI9niXlUlAUKj1mE
Tools used in this video:
R134A Gauge Set with Vacuum Pump: https://amzn.to/4lhMXqj
1234YF Gauge Set:https://amzn.to/3WWxd3rMy
R134A Gauge Set: https://amzn.to/3R4IGKz
Vacuum Pump: https://amzn.to/44Rnkql
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I source all of my service data from the same place that professional shops do. You can as well: https://www.pntrac.com/t/SENKSUZKRktDSEpOTEtGQ0dKRk9LTw
#ACDiagnosis #VehicleAC #AutoRepair #diycarmaintenance #airconditioning #acrepair
Questions? Send your question or schedule a call here: https://tazet.com/repairgeek
Chapters:
00:00 What we are going to cover in this video
00:42 How AC works
2:39 AC system components and functions
6:34 Make sure the compressor engages
7:03 What keeps an a/c compressor from engaging
11:06 How to attach the manifold gauges to the vehicle.
13:56 Static system pressure information
14:29 Reading system pressures
15:25 Ambient temperature information
16:53 Low side pressure normal/High side pressure normal
17:41 Low side pressure too low/High side pressure too low
18:23 Low side pressure too high/High side pressure too high
19:50 Low side pressure too high/High side pressure too low
21:54 Low side pressure too low/High side pressure too high
24:18 Outro
Disclaimer:
The information, demonstration and any content contained in this video is for informational purposes only. The user Repair Geek makes no warranty, express or implied, regarding the effectiveness or safety of the contents of this video. In no way should the contents of the video, including the tools used, be repeated or tried by anyone. Viewers should only seek the help of a trained professional located at a licensed auto repair shop for any fix, modification, alteration, or any change to their vehicle. Repair Geek shall not be liable for any injury, damage, or loss to any person or property that may result from use of the tools, equipment, or any content contained in this video. In addition, there is no way to guarantee that the video is not altered or modified or is not in the final form submitted by Repair Geek and therefore, Repair Geek does not warrant that the video is unaltered or not modified. The links on this video to products are for informational purposes only and in no way are an endorsement of the safety or effectiveness of the particular product. Viewers understand that anything contained in this video or linked to or from this video is the sole responsibility of the viewer and in no way provides an express or implied warranty as to the safety or effectiveness of any linked tool, product, or video. Therefore, viewer agrees to release, waive, and discharge Repair Geek or anyone affiliated with Repair Geek, from any and all liability, claims, demands, actions, and causes of action whatsoever arising out of or related to any loss, damage, or injury, including death, that may be sustained by the viewer, or to any property belonging to viewer, regardless of whether the loss is linked to the use of the contents of this video, or otherwise and regardless of whether such liability arises in tort, contract, strict liability, or otherwise, to the fullest extent allowed by law.
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Tools used in this video:
R134A Gauge Set with Vacuum Pump: https://amzn.to/4lhMXqj
1234YF Gauge Set:https://amzn.to/3WWxd3rMy
Vacuum Pump: https://amzn.to/44Rnkql
Amazon Store: https://www.amazon.com/shop/repairgeek
Help support the channel, buy using my Amazon links
As an Amazon Associate I earn from qualifying purchases and your cost is exactly the same.
Questions? Send your question or schedule a call here: https://tazet.com/repairgeek
after doing the vacuum in prep to checking static readings, do you close the valves or keep them open?
EDIT: never mind, both valves closed
my low side dosent go down???
I used a recharge kit it was 0psi I put a tiny bit and it jumped to 60psi at 75° ambient. So I stopped
Compressor turned on once I put some in. Had it running for 15 minutes the pressure on low side just wiggles up and down +- 2psi high side also wiggles.
Even if I let it sit for hours pressure stays same on both side dosent equalize or change at all
Is my Compressor dead??
For "Low Low" scenario, it's also extremely common that the clutch is either bad or not kicking on from electrical issues.
thank you for all the knowledge you are sharing about car a/c maintenance, you have the best videos out there are this subject!
My car AC system does not start cooling once i start the engine and run it at idle! I notice the engine fan does not start working when i turn the AC on!The AC however, starts working and blowing cool air after about 4-5 minutes once the fan starts to work! Looks like the fan does not turn on immediately once i turn the AC on. I read an error code when i use a scanner saying "fan activation"
Could this issue come from the fan operation or its faulty control unit ?
Excellent video mate. Thanks for making it
what to do if there's contaminant in the refridgeration system?
Check your fuses relay cooling fans Ac fans on radiator when hot engine jump fans with hot wire make shure are operable
If orificed clogged or TXV closed will cause high side = high pressure which cause the high pressure safety valve to blow open on compresor most air conditioners TECHNICIANS don’t know what causes en they want to replace all AC COMPONENTS MOST LEARN how to operate AC charging stations not knowing how to troubleshoot simptoms (replace orifice tube new cars you have to replaced one hose cause the O,.T. It’s built n crimped inside the hose.
Oh my god this video will help me so much. Great for not getting ripped off at the local garage.
Why would my ac work fine in cooler weather but not work around 83 degrees +¿
What if LP side is fine, but the HP is too low? What is that?
Don't you lose some refrigerant in those long lines every time you test? Why not use something that has a much smaller pipe to gauge just to check the pressures, then use this type of gauge set if you are evacuating and adding freon or whatever?
@10:04 a shop that could quote possible issues they could run into and follow through on repairs like that could clean up and provide invaluable service. Part of the problem is the rot in American capitalism from top to bottom, not that I believe I have the solution for it.
I barely see water get in the system. I've seen many cars have AC overcharged.
One way to figure if the system is overcharged. This is a very common way to look at a vehicle.
Run the system on full blast. You will notice the cold air coming out to the vents from the beginning. But once the engine gets very warm, the warm air will come out from the vents.
Listen to the status of the fans and the compressor. Those fans will run on and off intermittently (a few seconds off/on ) and the compressor will be clicked on/off. This is the sign that an AC gets overcharged due to the sensor turns the compressor off.
If your vehicle AC will blow warm air most of the time, and the AC fans turn on for more than a minute or more, or they will turn on all the time, this is the sign your AC has an issue, or it needs some refrigerant charges in the system.