Technical fiat petra 1.9 A/C -lot of fiat experts are available in this forum

[sivaamu]

Iam having fiat petra 1.9.In my car a/c was working perfectly.Today morning suddenly a/c is not cool with following condition
1.compresser working
2.gas pressure ok
3.both inside&out side fan running
4.small hiss noise in side the blower area(like ac gas expansion noise-isssss),noise comes when compresser on ,noise gone with compresser off

lot of fiat experts are available in this forum-please give your valuable reply

 

[Peter Pick-Up]

Could be several things.
Maybe just low on charge....??
Anyway, don't use the A/C until you have it test at a decent car A/C workshop, a broken compressor is very expensive.....!!!
For more info look at:
www.autoacforum.com

 

[sivaamu]

gas pr.normal,compressure also running normal,may be fault with pr relief value- please give advice

 

[Peter Pick-Up]

How about the cabin filter, should be changed at least once a year.
A clogged filter restricts airflow a lot!
The pressure switch stops the compressor from running when the Freon (R134A) charge is to low, to prevent the system for breakdown.
Btw, the pressure alone is not that important, the charge level is more important!
Even when low on charge, the pressure maybe OK...!!
So go to a decent A/C workshop and have everything checked asap!!
I still think your system just needs a recharge, it has to be recharged every 2-3 years anyway to keep it working allright...!!