A/C service + pics...
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
Well I am taking mine in to my mechanic tomorrow and let him mess with it, it is too damned hot here. My blower works, the compressore engages, so I guess I have a leak and all the refrig leaked out. I think it must be a good size because I thinked it worked in the winter (defrost) and definatly worked last summer. So I want the leak found and repaired; don't want to have to keep throwing refrigerant at it every few months.
Thanks for the pics and write up!
Thanks for the pics and write up!
The bin behind the passenger seat holds a hose and large can of R134a just perfectly. I place a thermometer in my center vents, and I can fill that res in now time.
Instructor
Joined: Dec 2007
Posts: 156
Likes: 0
From: Powhatan Virginia
Frosty
Pro
Joined: Sep 2006
Posts: 702
Likes: 2
From: Conyers Ga
Also the OP doesn't mention if he evacuated the system or just "topped off" with possibly the wrong gas.If the orifice is plugged up, your high will be too high; and the low too low. There are plenty of charts available to give you where they should be. Most restrictions, if severe enough, simply cause the compressor to cycle excessively (more than 8 times per minute at 70 degrees). Since the evaporator isn't getting a full shot of gas, what gets in flashes off immediately and there's no oomph left when it reaches the low pressure switch.
once again Orifice = metering device ie: designed restriction.I usually check the harness for voltage with the ac turned on and then check the receptacle for continuity.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
" . . . the compressore engages, so I guess I have a leak and all the refrig leaked out . . . " The compressor won't engage if there's no gas (or even a low charge on the '90 and up.) Hopefully whomever you take your Vette to knows how it works and doesn't charge you for something it probably doesn't need (thinking about it, adding gas is probably a lot cheaper - less profitable - than fixing a broken temp door, so a good shop should be motivated to do what's necessary!).
". . . there is a charge psi somewhere printed on the system. Am I dreaming or does this exists. I remember getting the high side pressure number for my car somewhere . . ." The only thing printed is the weight of the charge. Operating pressures depend on the temp of the refrigerant which is determined by the temp of the air across the condensor. High side pressures that are 2.2 to 2.5 times that air temp are usually within spec and something to aim for if you're topping off and have no idea as to how much is in it. Otherwise, there are countless pressure/temp charts available, but the FSM is the best place to see what the engineers expect for your vehicle.
"It's normal for the suction (low side line ) to get "frosty" more or less with humidity in the air . . . " If there's frost on the suction line, there's frost on the Evaporator. Moisture that has condensed out of the air and has turned to ice (frost), indicates a problem. As air is blown across the Evaporator, the low pressure liquid boils and absorbs heat - it isn't a heat exchange process (such as that which occurs within the radiator or condensor where the stuff through it gives up it's heat to the air). Rime on the Evaporator blocks air flow so you don't get as much heat absorption as you would without it. That translates into a higher vent temp. If you see frost, fix it - in most cases it's just a bad switch.
". . . there is a charge psi somewhere printed on the system. Am I dreaming or does this exists. I remember getting the high side pressure number for my car somewhere . . ." The only thing printed is the weight of the charge. Operating pressures depend on the temp of the refrigerant which is determined by the temp of the air across the condensor. High side pressures that are 2.2 to 2.5 times that air temp are usually within spec and something to aim for if you're topping off and have no idea as to how much is in it. Otherwise, there are countless pressure/temp charts available, but the FSM is the best place to see what the engineers expect for your vehicle.
"It's normal for the suction (low side line ) to get "frosty" more or less with humidity in the air . . . " If there's frost on the suction line, there's frost on the Evaporator. Moisture that has condensed out of the air and has turned to ice (frost), indicates a problem. As air is blown across the Evaporator, the low pressure liquid boils and absorbs heat - it isn't a heat exchange process (such as that which occurs within the radiator or condensor where the stuff through it gives up it's heat to the air). Rime on the Evaporator blocks air flow so you don't get as much heat absorption as you would without it. That translates into a higher vent temp. If you see frost, fix it - in most cases it's just a bad switch.
