I love the fact that you didn’t edit out the part where you diagnosed that it was the hot/cold control knob... I like the humbleness and your sense of humor as well
Because of your videos, I was able to go from no AC experience to successfully completing a complete AC overhaul on my beloved 95 chevy g20 conversion van, which has front and rear AC. I replaced the compressor, pressure switchs, evaporator, orrifice tube, expansion valve, o-rings, flushed everything, vacuumed, and recharged. I learned the hardway that Santech is not better than Acdelco, and your diagnosing methodology came out in me and I was able to use the gm service manual to deduce that my recent ac issue was due to a bad high pressure switch that I installed new during the overhaul of last summer. Well ysterday I completed and it is working correctly now, so I thank you R&W!!
I realize that this video is old, but it is one of the best car repair videos I've seen. The on-air guy helps with diagnostics and repair. There are a lot of repair videos out on youtube (and that is great), the issue for us do-it-yourself people is the diagnostics. Great video!
That was the most fulfilling outcome for education. You go past the physical refrigerant system and diagnose electronics. That’s what it takes sometimes thank you for that surprise
Great job in explaining. You were technically correct explaining how the low pressure switch has an open or closed connection to pass electricity. Very good explaining technical in simple dialogue. That is what makes you a technical teacher! thanks for your time and effort! Keep up the good work. 👍
Would have recommended unhooking heater hoses from heater core for a cheap work around for summer. At least the owner could get some a/c. Would rather be cold than hot any day.
..Very Good Explanation of how the AC System works and How to Diagnose it !!! You did a Better job than most of the so-called "pros" on RU-vid! This is a handy video because it helped me find out that a pressure switch is bad on a '94 Crown Vic. Thanks...!!!
I'm jelly of your Vic bruh. Tried to buy a police interceptor but somehow ended up with a Jetta - It's black - and Sacramento triple digit summers with no AC in a black car is a ticket to roadside cremation.
This is probably one of the best AC videos on youtube. This guy breaks every aspect of the system down, how it should work, things to check and expected outcomes and possible issues. We even got to watch him diagnose a vehicle. Wow this was great and more people should be subscribing to this guy. I feel like I just got trained like a mechanic!
Skills! Thank you for sharing. Very clear and concise root cause analysis. It would be great to have a series of these videos with different root causes and labeled with the root cause so the viewer could watch and follow based on the readings/results they are getting.
Great job, I have watched numerous videos explaining the automotive A/C cycle, 1st time it was mentioned that the actual on/off cycle of the compressor is controlled by the low pressure switch. Makes sense, a pressure too low the designed spec of the compressor could damage it and therefore shuts off the 12 v feed to the compressor coil clutch. Keep up the great work!!
On this particular system that is correct., sorta. The switch he described is actually a Cycling Switch not a low pressure switch. It has a range usually between 22-44 Psi. where the compressor will cycle. Other systems, mostly expansion valve types will use a thermostatic switch to prevent freeze up of the evaporator core and a low pressure switch to prevent compressor damage in the event of refrigerant loss. International trucks use temperature thermistors to sense the inlet and outlet refrigerant temperature at the evaporator and a high side pressure transducer to actuate the engine fan and turn off the compressor in the case of over pressurization. This is all controlled by the ESC body Controller ECM. I give these examples not to confuse you but to show that A/C systems are controlled differently depending on how they're engineered.
That was a great tutorial. Pulling a dash apart is a really big deal. I plan on recording mine if I have to do it just to help eliminate missing steps during reassembly.
Gr8 video mate. My compressor making noise. A/C was working good. I turn A/C on to cool motor down as radiator fans turn on(I know they come on at 109°c but I don't my motor getting that hot). Well didn't cool down, but didn't have noise. But everytime I try the noise get worst. A new compressor here in Australia $450 just to buy. Car exactly the same as a Pontiac G8 2008. 350000kns. It a pain to drive in the rain
Good video. Its interesting how all the manufacturers went to plastic blend doors with servos. The old cars used metal doors with vacuum actuators and they lasted the life of the vehicle. I currently have the heater box out of my 05 Ram replacing the all the blend doors .
Thank you for your time and knowledge, but I didn’t see a link to where you got the universal hood prop rod. You are one of my new favorites. Very understandable, thanks again
Great video.....a lot of twists and turns. I was sure it was going to be the potentiometer.....nope. Then I thought the blend actuator....nope. You explain things in a easy to understand way. Thanks!
Ratchets And Wrenches thank you for such great explanation of the system. I have learned many things from you. I'm just a do it yourselfer that likes to save money and fix its own cars. Good video!!
Great job at explaining how to troubleshooting and using the gauges. But to me that’s why I don’t buy FORDS, as they design things that take to much effort to fix and repair.
My son’s 98 Ranger had this issue. We got a sturdy blend door in a kit from a website called heatertreater.com I think. You have to dremel an opening in the plenum to get it in but then patch it back after. Worked for the last two years he owned it, and no dash removal.
At 9:57 of the video there is an error in the psi conversion chart on the fourth line in the high side column. What a goofy thing for me to notice, ha ha. It looks like higher humidity pushes numbers up a little on both sides. Another classic video, thanks for posting.
Great video. My Lexus gx470 2007 is blowing out of defrost only. Middle vents not at all. The end vents do blow but weak. Passenger side cold. But not real cold. Drivers warm. I thought it was the actuators. I have tested and they seem to be ok. Was going to check freon tomorrow. I was trying to see why it was not blowing out of middle vents at all. Frustrating.
Excellent video explaining how A/C systems work. Can you give a video presentation on converting a R12 system to R134. My 1991 Toyota is leaking the R134 installed. Thanks.
Dumb question: Why don't you just block the heater hose? If still no cold air, then the blend door has failed in the heat only position rather than somewhere in between. If so, perhaps the door can be moved with a borescope.
Brillant tutorial. The only thing missing in the video, you didn't check the low side pipe temperature to the touch by hand to see if it is actually doing any cooling at all before you jumped into the cabin and questioned the dash temperature control potentiometer. But all else was first class presentation.
My old 1993 Mustang LX had this interesting problem: the electric condenser cooling fan was broken, which made the high side extremely high. It was so high that the compressor was basically locked so when the clutch engaged, the rubber damper/coupling in it shredded. It was pretty easy to fix: replace the fan and the clutch. I'm surprised the compressor had no high pressure bypass, but maybe it's wishful thinking on my part (or it was broken).
Thanks buddy... you are a genius. You explain real good. Appreciate your video. I' am your fan now. You are real good at your job and you explain really good too.
Hi, Thanks for your perfect explanation Can you please advise why When I switch on AC the compressor will click three to four times before back to normal
if the orifice tube is clogged would that make the high side high and the low side low? thanks for the video im getting my ASEs and this is very helpful!
Great information shared brilliantly. I got my cheapo gauges but got a surprise! Hight pressure coupling would not connect to my Chevy avalanche high side. Checked the gauges on a different can and they fit ?! Upon further inspection I discovered that the coupling second ring was not round? Felt hexagonal? Do I need an adapter to fit Chevy truck?
Haha love your using a pry bar for a pointer! So would uneven static pressure before starting tell me if the orifice tube or expansion valve is restricted?
Good info, how come you didn't discuss the high pressure switch much? Seem like you covered the low pressure switch issues but didn't talk much about high pressure issues.
I work on the building side of HVAC and I wasn't sure if there was anything different between auto and buildings. Turns out, no it's the exact same just smaller scale and more of a cluster fck. Also the accumulator is called a liquid line filter dryer from where I'm from.
Thank you so much for the video. My 2002 lexus sc 430 has 95psi on the low side and 100psi on the high side when the compressor is running. Do you think it is a bad compressor check valve or a bad ac compressor or may be both expansion valve and compressor is shot? I vaccumed the system and made sure it didn't have any leaks before filling it up with 23oz of refrigrent. I really appreciate your feedback. thank you
Wow good video. Wondering if you could help, my ac works sometimes(perfectly) and sometimes just refuses to. Have to restart the car and play around to get it to work. Any idea what problem that might point towards?
Hello. Thank you for theres video. It's very informative. I have a 2003 jeep liberty 3.7L. The ac speed working about 2 months ago. When it worked it was very cold. There's no leaks, the compressor works, has plenty of freon, I was told the pressure's are good. The orifice tube is in the hose, warm on the condenser side, cold on the evaporator side up to the evaporator. The hose from the evaporator to the accumulator is warm, the accumulator is also warm as well as the side to the compressor. It blows warm air just a bit cooler than ambient temperature. Does anyone have any ideas on what could be the problem? Any help is appreciated. Thank you.
So, I figured ot the problem. The condenser fan wasn't turning on. The harness was loose. Once I got the fan running it started cooling. Thought this might help someone.
Please what do you suggest is the best solution when the compressor is faulty and has low pressure to pump gas? Do you support flushing the condenser and changing its drier, or do you support changing the condenser completely? Do you also think there's a good chance for the AC condenser to still be ok & reused once the compressor knocks (ie. When the compressor is faulty)?
The question is not quite on the subject of the film, bcs it is about refrigerant oil amt, but I think this is the right audience for the inquiry. Please can someone solve this arithmetical puzzle from the Shop Manual? It states in the Manual (car is 2001 Saturn SL2): The Saturn air conditioning system requires 150 ml (5.07 oz) of PAG compressor oil. Service compressors have 65 ml (2.20 oz) of PAG oil installed. New oil quantities must be added to the system during component replacement and conditions stated as follows: With no signs of excessive oil leakage, add: Compressor: Remove, drain, and measure oil. Drain the replacement compressor. Add the same amount of new PAG compressor oil drained from the removed compressor to the replacement compressor. Evaporator: Add 67.5 ml (2.25 oz) of new PAG compressor oil. Condenser: Add 22.5 ml (0.75 oz) of new PAG compressor oil. Receiver-dehydrator: Add 30 ml (1 oz) of new PAG compressor oil. Open the R-134a source valve(s) and allow 0.50 kg (1 lb) of liquid R-134a to flow into system through low side service fitting. As soon as 0.50 kg (1 lb) has been added to system, start the engine, set the mode control to vent, the temperature lever to full cold, the blower speed on high, and push the A/C compressor button to the On position (A/C control button light On). Slowly draw in the remainder of the refrigerant charge 0.23 kg (0.5 lb). The total system charge is 0.68 kg (1.5 lbs). I'm reading all that information in my Shop Manual and don't get this: If the total amount of refrigerant oil is 5.07oz and 2.25oz goes into compressor, then for Evaporator, Condenser and Receiver Drier is left only 2.82oz (5.07-2.25=2.82oz). But if to add what is recommended for Evaporator, Condenser and Drier it will add up to 4.0oz (2.25+0.75+1.0=4.0oz), with the total in the system 6.25oz (4.0+2.25). How much oil on total is in the system: 5.07oz or 6.25oz? Where I'm wrong? I'm replacing everything besides the Evaporator and Compressor (I'll remove it and flush w/solvent though), those I'll just flush with solvent. No info on Refrigerant Oil under the hood or in owners manual, or in Haynes book. Thank you.
