[gpa]

Originally Posted by abhibh

I have the same problem in my Alto. In city drives or idling the AC wont shut off even for 2 hours, but on highways after every hour i had to turn off the blower for 10 mins and start it again.

Looks like the thermostat is faulty. Also try and not turn the knob to the coldest position but leave it one step above to prevent this frosting and the rise in temperature after a while of running the a/c.

[udaydesai]

Hi
It is the thermostat problem which is at fault, due to which there is ICE formation. I had the same problem in my zen. My AC mech is comming this sunday to change the thermostat.
will keep you posted on the development.

Uday

[Jaggu]

First check the gas level, if over filled the system will freeze up on extended run. This is what you can do for simple check: switch off the compressor for few minutes and see if the cooling returns, do this after the ac stopped working on its own.

[deky]

Originally Posted by jav

This is mostly caused by a faulty thermostat which does not cut off when the temperature drops or can be blockage of the coils as mentioned in the above posts, Get it checked by a good A/C mechanic or service center.

Thank you, will do. The cars due for 20K service in a few days.

Originally Posted by SirAlec

change the settings on the expansion valve. if found faulty replace.

What does an expansion valve do? can I change the setting myself or take it to the mechanic?

Originally Posted by gpa

Looks like the thermostat is faulty. Also try and not turn the knob to the coldest position but leave it one step above to prevent this frosting and the rise in temperature after a while of running the a/c.

Thank You, but dont you think there should'nt be a problem at the knob being at the coolest? I mean if there is a coolest, the system should be designed in such a way that it should be able to stand those temperatures!!!

Originally Posted by udaydesai

Hi
It is the thermostat problem which is at fault, due to which there is ICE formation. I had the same problem in my zen. My AC mech is comming this sunday to change the thermostat.
will keep you posted on the development.

Uday

If my problem is rectified earlier will post it here too, thanks.

Originally Posted by Jaggu

First check the gas level, if over filled the system will freeze up on extended run. This is what you can do for simple check: switch off the compressor for few minutes and see if the cooling returns, do this after the ac stopped working on its own.

Its a gradual decrease in temperature. And yes after stoping the AC for a while, the colling gets back to normal.

[Jaggu]

Originally Posted by deky

Its a gradual decrease in temperature. And yes after stoping the AC for a while, the colling gets back to normal.

Ask a competent mech to check for all usual culprits for refrigerant freeze up.

[SS-Traveller]

IMO this issue faced by so many here is probably being caused by the high humidity in the atmosphere. With a partially clogged and dirty cooling coil (something like this),

http://www.team-bhp.com/forum/attach...2-abcd0015.jpg

the moisture tends to condense on it and freeze; this causes the thermostat to cut the compressor out, while the ice formation leads to a reduced airflow.

A simple AC service costing around 1.5 - 2k (including cost of gas) should solve this problem.

[abhibh]

Ok a bit of history of my car:

- Its 9 years old
- AC has been serviced maybe max 2 - 3 times (not sure) in 9 years
- AC gas never leaked and i have never got it refilled.

One thing i am still unable to understand is that if AC / engine or anything is getting overheated then why does the air from blower is less ? No matter AC on or OFF the blower should blow air at same speed.

[SS-Traveller]

Originally Posted by abhibh

Ok a bit of history of my car:

- Its 9 years old
- AC has been serviced maybe max 2 - 3 times (not sure) in 9 years
- AC gas never leaked and i have never got it refilled.

One thing i am still unable to understand is that if AC / engine or anything is getting overheated then why does the air from blower is less ? No matter AC on or OFF the blower should blow air at same speed.

AC service once after every 3 summers is generally required - earlier if you tend to drive in fresh air mode.

When there's icing up of the cooling coil, the air flow through the coil becomes blocked - therefore blower output into the cabin reduces.

[jav]

Originally Posted by abhibh

Ok a bit of history of my car:

- Its 9 years old
- AC has been serviced maybe max 2 - 3 times (not sure) in 9 years
- AC gas never leaked and i have never got it refilled.

One thing i am still unable to understand is that if AC / engine or anything is getting overheated then why does the air from blower is less ? No matter AC on or OFF the blower should blow air at same speed.

Does your a/c cut off when it gets cold or does the compressor keep running even when the air flow reduces, if yes then usually its the thermostat which is faulty.

[deky]

I gave my Car for 20k service today and reported the same problem. The mechanic agreed its either the expansion valve or the thermostat which is faulty. And assured he will have a look and would not happen again.

I will let you know the outcome later.

[Aashutosh]

friends,

my query is slightly off topic, but require your help. I own a 2001 santro, whenever I switch on the AC, the engine RPM shoots up. Is this normal?

Plus there is some noise when I switch on AC. As per mechanic, its clutch bearing of AC that is causing the noice.

Otherwise AC is perfect.

Can you please guide/help, how I sort this out.

[gpa]

Aashutosh,

The increase in the RPM of the engine is normal. However, if you hear noises that indicate the compressor bearings are on their way out (which might be the case as your car is 8+ years old) then you can either have the compressor serviced or replaced.

Regards,
gpa