zerep

my a/c stopped cooling last week and is now blowing hot air. i tried recharging the system but the there does not seem to be a leak of the refridgerant because the gauge showed it was not low.
now for the variable, i do have a minor leak in my engine coolant. Leading from the G12 coolant resevoir, there is a y connector and a hose that runs to the engine block (part numbers 06a-121-069-c and 1j0-121-087-e). These parts need to be replaced and i will do so this weekend. i have kept the G12 coolant level within acceptable levels and i can hear the compressor clutch kick in when the a/c is turned on. so if i'm not low on coolant or refridgerant and i can hear the clutch kick in, what would be the next items to consider? would you all mind sharing your expertise? thanks in advance, jaime.

N9909E

Jaime, give me a call. If the compressor clutch is cycling the freon is OK.

GorTT

some other items too, but that sounds most likely - fan controller, fuse, or fan itself - try doing a search, should be pretty productive.

N9909E

It's 90 deg.+ here. If the cooling fans were inop it would overheat in a heartbeat.

J. Patterson

When the compressor clutch engages, The low side pressure should fall (to about 60psi or so) and the high side pressure should rise. ( to about 200 psi or so) The fans are not necessary for cooling when the car is in motion. (but they do help if you are going slow and it is a hot day) The compressor must move gas. You can tell if it does by observing the low side pressure. (at the larger charging port) If it falls lower than 50 or so, you are simply low of refrigerant. If it does not fall but the compressor is turning, you need a compressor. There is a pressure switch that wil disengage the compressor if the pressure is too low. (below 30 or so) Typically this will make the compressor cycle on and off.
WARNING--- When adding refrigerant. do so fairly slowly with the can upright or with the valve just barely open if you want to charge liquid into the system by turning the can upside down. Liquid freon can not be compressed and will damage the compressor valves. ( if the hose gets so cold that frost forms on it you are charging too fast)

Freon gets cold when it expands.(absorbs heat) There is a valve at the inlet of the in dash coil that meters refrigerant into the coil as it expands into a gas.
It gets hot when it is compressed. The compressor sucks the gas out of the evaporator coil in the dash. (Heat is concentrated) and pumps it to the condensor coil. The fans at the radiator (the condesor coil) remove heat from the compressed freon and it condenses into a liquid state. The refrigerant then flows back to the evaporator coil in the dash. The blower inside the car lets the in dash coil (evaporator) absorb heat from the air in the car.

So The refrigerant is simply moving heat from one place to another. Goes round and round over and over.

Got it?

GorTT

It's hot here too (100+); I had the same symptom about 3 years ago, and yes, the engine did run hot but it also affected my ac exactly as is being described.

N9909E

Wanna bet? His engine's not running hot. Probably the air mixing flapper valve.

NOLA TT

I'll be seeing Gary tonight - I'll pass it to him... and anytime you need it, I'm just an email away - scors1@yahoo.com.

zerep

Thanks Gary. I'll give you a call this evening. And you are right, the car is not running hot.

zerep

this explanation helps. so what if i was seeing more than the usual condensation puddling under the car? would that indicate a problem with the evaporator/condensor coil?