AC cooling OFF and ON

[jerico]

Guys,

Yesterday when we are cruising the highway, our AC just cut off and only fan are functioning, i tried switching it off and on and same problem. After 5 minutes of whitout AC suddenly it cools again, i can also notice the air coming from the vent. It is like a white smoke and eventually disaapears. But this time, the cooling effect is lessen. This morning, the AC is very low and it takes time to cool again. I talked to one technician, he told me that there could be a problem on Evaporator Sensor and TOPPING UP the AC Gas would not do. .. Any advise would be appreciated.

Thanks in advance.

Regards,

JErico

[Hamfisted]

It sounds like your AC system is just a little low on freon (R134a). Go to Walmart and buy one of those R134 cans that has the hose and gauge already on it. Check the freon level in your system first before you go spending big bucks at the shop. The low pressure connection port is up by the firewall on the passenger side. Make sure the pressure needle on the freon gauge is in the blue zone (30-40 psi...) with the engine running and the AC compressor ON. Add R134 freon to the system to bring the low side pressure into the blue range on the gauge. Good luck.

Also, when was the last time the cabin air filter was changed? That's another maintenance item to look at every year or so.





-Mike

[Mookie]

Evaporator temperature sensor was the part the tech talked about. It senses when the eaporator is icing up which would explain the lack of cooling. Sensor cuts out the compressor to prevent icing.
Icing can be caused by low refrigerant level, need to have the pressures checked.

Icing can also be caused by low air flow across the evaporator. Depending on the year of your car, the ventilation system microfilter could be dirty. replace filter first, cheap enough. Might solve your problem.

[jerico]

i did some more observation on the car so we can narrow down possible problem on my AC. It seems that the oncoming air from the vent is freezing. I notice it when i try to put my hand on the vent. It's like touching an ice. Then after a few minutes of freezing, the cooling effect slows down till i got only blower fan. It seems that it is cutting off in freezing state. As MOOKIE suggested, i'll try to check the microfilter and the refrigerant level. any additional advise is highly appreciated.

Thanks.

[land9]

it could also be too much gas in your system - that'd cause the system to cycle on and off quicker because of the excess pressure
have you had it recharged lately and how long has it been doing this?

[jerico]

guys, my AC is running cool again but this time it does not freeze. The refrigerant level is low so they added another 4 units of R134A and dye, just in case of leaks,my AC is running well now. the technicians says to observe the temperature. They had provided me the digital thermometer for observation just in case it would turn up freezing again but upto now no prob. thanks for all the advise and help. Really appreciate it specially for a newbie like me.