Car AC Diagnosis of Various Symptoms Dedicated Thread

[afnan.bashir]

system may be over charged. The switch prevents pressure over limit and kills compressor. Once it comes in normal range it works

[afnan.bashir]

If you have it recharged already then go with xulfiqar method else there is a sticker on your hood .
See following image. Add appropriate oil on items you change. Replace drier once it is removed. If your compressor failed replace condenser because particles block the condenser and are impossible to her them out of serpentine condenser. These oil capacity are for items you replace or if you completely flush everything. Once your ac system is open make sure if your compressor failed you change your txv. Its cheap and you don't want to open your system later for this

[galant1]

the charge needs to be recovered and then weighed on scales

In case system does not have gas then how to give the system 600-650 grams gas means how to weight the ac gas before the filling and then fill with measured value?

[afnan.bashir]

In case system does not have gas then how to give the system 600-650 grams gas means how to weight the ac gas before the filling and then fill with measured value?

Yes it is 600 to 650 grams and see previous post for oil

[galant1]

Yes it is 600 to 650 grams and see previous post for oil

I read these stuff earlier. Now I have some confusions:

1. I have not new compressor for measuring the actual oil quantity. If I remove the compressor and what will be exact amount of oil that should be filled in compressor after draining all old oil from compressor.

2. AC Guys charge the gas in their way- you know better then how can we measure that gas from their cylinder will be according to 600-650 grams?

[Xulfiqar]

Well yes I think so because split units are heavy on electricity. They are some 2kwh may be if I am not wrong. Will this work of we have efficient condenser and evapourator. Someone said to e go and.buy a smuggled split unit you may need some.work on them but commercial units here are no where to those Russian ones son I thought if a country can make water cooler (Orange plastic baraf wala cooler with coper tubing placed inside.)
what's bad in making aC.

all refrigeration systems are heavy on electricity - I am also into the business of data networks and deal with a lot of BS of cooling down server farms with low cost solution - so the ideal way is to optimise airflow and control temperature throughout the range.

Placing of the evaporating unit and condensing unit also play a role in this and so do air distribution, also remember that cold air is very heavy and requires assistance to move.

[afnan.bashir]

all refrigeration systems are heavy on electricity - I am also into the business of data networks and deal with a lot of BS of cooling down server farms with low cost solution - so the ideal way is to optimise airflow and control temperature throughout the range.

Placing of the evaporating unit and condensing unit also play a role in this and so do air distribution, also remember that cold air is very heavy and requires assistance to move.

Nice info so do you think this is I worth doing diy or I will end up with something useless? I was also thinking of using car comp but rpm is something complicated in conjunction to horsepower compressor will need

[SER_GTR]

Well yes I think so because split units are heavy on electricity. They are some 2kwh may be if I am not wrong. Will this work of we have efficient condenser and evapourator. Someone said to e go and.buy a smuggled split unit you may need some.work on them but commercial units here are no where to those Russian ones son I thought if a country can make water cooler (Orange plastic baraf wala cooler with coper tubing placed inside.)
what's bad in making aC.

I Guess It Will COnsume Around Same W As You Split If You Need A Decent Cool In Room..... A Too Much Small Compressor Will Not Be Suffice To Get That Room Cooled...So Calcluate KwH And W If It Runs Continuous

To Me They Always End Up ALmost Thinking In End To Get SPLIT ...Till You Have A Very Small Room And Need Cooling In That

Then You Can Make It Work Somehow

[SER_GTR]

I read these stuff earlier. Now I have some confusions:

1. I have not new compressor for measuring the actual oil quantity. If I remove the compressor and what will be exact amount of oil that should be filled in compressor after draining all old oil from compressor.

2. AC Guys charge the gas in their way- you know better then how can we measure that gas from their cylinder will be according to 600-650 grams?

1.Measure The Amount Of Oil Drained From Old COmpressor And Add 20ml More Into It...It Will Work.....You Compressor SHould Have Oil Quantity Marked...If Not...You Can Always Find It...What Is Compressor Model???

1. By Weight Scale...Or Get Same Amount Of Gas Filled In Empty Cylinder.....

[SER_GTR]

@capsat @SER_GTR @afnan.bashir @Xulfiqar

1- Please explain the low and high side guages connection procedure or sequence.

Today i visited few ac workshops, all of them said, they check/recharge gas level by low side guage only, because connecting high side gauge wastes/leaks the gas or something. I am pretty sure that they don't know how to connect it properly.

2- blower fan speed is super fast (relayed) at 4 position and normal at 3 position. Pressure readings, at 1500 rpms, should be checked at which blower speed?.

3- receiver drier bottle, inlet and outlet pipes both temperature should be equal?. Can we check that with DMM with temperature probe?

I read all earlier posts, so now i have learnt basic idea of other things, but i am confused about this. I have r134 system.

If He Test Only One Side.....You Have A Licence To Call Him Road Side AC Mechanic Or Barsaati Mendak Of AC Work....B.S If He Say High Side Leaks Gas...Probably He Don't Wanna See How Much Head Pressure Car Raised ...So Its Better Not To Use AC If You Gonna Get Recharged Like That....You Can End Up Blowing Lines If Head Pressure Is Raised Due To Any Reason And He Remain Blind On It

Super Heat And Sub Cooling Is CHecked But For That You Need Clamp Type Thermometer With Insulation So It Won't Get Affected With Atmosphere.....Thats An Expensive Piece Of Tool In HVAC.....

[wasim625]

Nyc info... Will be posting my AC issues here

[nabeelkhan]

bhai muje ye batao k Cuore ka AC jab bhi on karta hu car ki race thori c increase ho jati he.. is it normal ya meri car k sath koi problem h ?

[afnan.bashir]

bhai muje ye batao k Cuore ka AC jab bhi on karta hu car ki race thori c increase ho jati he.. is it normal ya meri car k sath koi problem h ?

it is normal. It is done so that your car may not stall because of excessive compressor load

[afnan.bashir]

@ser_gtr well why do you measure head pressure on 1500 RPM? if this pressure is low at idle this means cooling will be low too rite?

[anc]

Would it help increase the cooling of AC if we block the Heater pipes?

[abdullah.sheikh.1848]

Hello everyone. I recently got my ac serviced and gas refilled. Its working very well, even in the afternoon with the temp higher than 42c its extremely chilly, but the issue is its not cooling on idle and when the ac is on the rpm gets unstable and goes very low and the car vibrates bcz of a shaky rpm and with the ac on the car gets a really heavy. The car is a 2000 model Honda civic vti oriel. Help would be really appreciated

[Xulfiqar]

I read these stuff earlier. Now I have some confusions:

1. I have not new compressor for measuring the actual oil quantity. If I remove the compressor and what will be exact amount of oil that should be filled in compressor after draining all old oil from compressor.

2. AC Guys charge the gas in their way- you know better then how can we measure that gas from their cylinder will be according to 600-650 grams?

1 - discharge ac compressor oil as the manual tells you, rotate the compressor clutch by hand till it ejects all oil and let it drip into a container for 30 minutes, measure that oil. - put in about 50 or 60 ml oil in the compressor and rework it by hand with compressor upright and remove that oil too (this was flushing) - now fill in the required quantity of oil - add from suction port.

2 - use digital weighing scales to weigh the gas container - do not ever charge the unit with liquid, leave the cylinder upright and let it suck in vapour only. close off the unit at 80% capacity and let the unit stabilise for 20 minutes at maximum load, then add the remaining.

[Xulfiqar]

Nice info so do you think this is I worth doing diy or I will end up with something useless? I was also thinking of using car comp but rpm is something complicated in conjunction to horsepower compressor will need

car ac units are no where near the BTU rating required to cool down large rooms unless you have passenger bus sized equipment.

[SER_GTR]

@SER_GTR well why do you measure head pressure on 1500 RPM? if this pressure is low at idle this means cooling will be low too rite?

Yes But On Pressure Gauge You Have To Exactly Do It In Order Not To Overcharge....It Can Also Increase Suction And Will Also Make U See Your Extreme Head pressure

If You Charge By Weight...You Can Just Charge Slowly But Revving Is Recommended .....Its MUST If You DOn't Know Quanity To Charge And Totally Depending On Manifold Gauge Set Readings

[wasim625]

So,
Today i noticed at peak 2 p.m my car's AC stopped working. It was like clutch was not all the way engaging. It engages at IDLE rpm and when i press accelerator it disengages and never engages back. This problem is there when car is stopped.
Once car is on highway running at any speed the AC behaves normal.
To me that looked like the condensor was unable to dissipate heat from the refrigerant and which ended up less cooling effect inside the cabin. Moreover, i couldn't get why the clutch was only engaging at idle RPM any RPM above idle disengage the clutch. It is normal by the way but the problem is once it disengages it engages back on its own will lol i mean any time it likes to. What i think is it should disengage and then engage back to start cooling but at that time 2 p.m it wasnt.
Later at 5 pm it was again behaving normally like nothing happened LOL