'94 LT1 A/C not working
Thread Starter
Racer
Joined: May 2003
Posts: 348
Likes: 1
From: Hermosa Beach, CA
'94 LT1 A/C not working
I just got my car back on the road after sitting for a year and a half only to realize that my A/C is no longer working. This probably is a result of not having run the A/C in that time period which allows seals to dry out and leak (true or not?). In any case, where is my most likely culprit for a leak so I know what to replace before I refill this? Thanks.
Also, how do you traditionally look to see if an A/C component looks to be leaking? Do you have to use a UV dye or are there telltales?
Also, how do you traditionally look to see if an A/C component looks to be leaking? Do you have to use a UV dye or are there telltales?
Melting Slicks
Joined: Feb 2005
Posts: 2,135
Likes: 0
From: Sebastian Florida
St. Jude Donor '06
Seals on compressor, followed by evaporator. Do NOT try and run the car with no refrigerant or you will replace your compressor, but chances are your compressor is bad to. There are seals inside your compressor, that can go bad, evaporator might need to be replaced and if you were running R-12 and go to R-134a, they will have to be replaced, along with having your lines vacuumed out.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by Randy93
Seals on compressor, followed by evaporator. Do NOT try and run the car with no refrigerant or you will replace your compressor, but chances are your compressor is bad to. There are seals inside your compressor, that can go bad, evaporator might need to be replaced and if you were running R-12 and go to R-134a, they will have to be replaced, along with having your lines vacuumed out.
Pro
Joined: May 2005
Posts: 525
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From: San Antonio TX
One way you can tell if you have leak if you find a film of dirt and oil around your freon line connections or behind the compressor pulley. As your freon leaks, it also leaks oil and the oil attracts dust.
But the best way to detect it is to have a shop use some kind of freon sniffer. I don't know the name of it, but it is a probe that they pass over your lines to find the leak. This would be your best bet because you can't get a visual inspection of all places such as your evaporator (without removing the airbox).
I personally don't like to use dye. That's just me. The only thing I want swimming in my freon lines are freon and oil...
But the best way to detect it is to have a shop use some kind of freon sniffer. I don't know the name of it, but it is a probe that they pass over your lines to find the leak. This would be your best bet because you can't get a visual inspection of all places such as your evaporator (without removing the airbox).
I personally don't like to use dye. That's just me. The only thing I want swimming in my freon lines are freon and oil...
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by bowtie350_428
One way you can tell if you have leak if you find a film of dirt and oil around your freon line connections or behind the compressor pulley. As your freon leaks, it also leaks oil and the oil attracts dust.
But the best way to detect it is to have a shop use some kind of freon sniffer. I don't know the name of it, but it is a probe that they pass over your lines to find the leak. This would be your best bet because you can't get a visual inspection of all places such as your evaporator (without removing the airbox).
I personally don't like to use dye. That's just me. The only thing I want swimming in my freon lines are freon and oil...
But the best way to detect it is to have a shop use some kind of freon sniffer. I don't know the name of it, but it is a probe that they pass over your lines to find the leak. This would be your best bet because you can't get a visual inspection of all places such as your evaporator (without removing the airbox).
I personally don't like to use dye. That's just me. The only thing I want swimming in my freon lines are freon and oil...
The core you are talking about infront of the radiator is the condensor core, the evaporator core is on the firewall. If it sat that long and something wont go, id have the whole system flushed and new oil and gas put in. The best way to protect against compressor failure is to make sure the oil and gas are in there. Also,it may apear to be charged, but the system will need at least 6 PSI on the low presure side to carry the oil around (low presure starts after the orfice tube,through the evaporator,then back to the compressor) If it is under 6 PSI it will not let the clutch engage on the compressor to prevent damage to the system due to lack of oil flow.
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Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by cresus
I actually checked it and the system is charged. So my guess is that one of the switches is broken preventing it from turning on. I'm unsure of how to test it though.
Im not too sure about codes on A/C. But you can test by pulling the plug off the presure switch,and joining both terminals in the plug. Im not sure where they will be on your car, cause im in Australia and my 94 is right hand drive so the A/C system on mine is on the left hand side. But it will be back towards the firewall on the right hand side somewhere,on the A/C pipes. If you join that and the compressor cuts in, youre probably too low on gas, but if youre sure the gas is good then get the presure switch checked.
Racer
Joined: Oct 2003
Posts: 429
Likes: 0
From: Plains Ga.
A/C ok?
Start your car and let it warm up first. Then turn your a/c on MAX cooling. Look at the front of the a/c compressor to see if the clutch is engaging. From what you described ,it probably isn't. If it isn't engaging,
go to your accumalator(aluminum cylinder on passenger's side near firewall) and disconnect the plug on the low pressure switch. I use a paper clip or a piece of wire to jump this plug out to see if the clutch will engage. If it does, then you probably are low on freon or a bad switch. If you are low on freon, add as needed. You will need a set of a/c guages and a leak detector(sniffer). If the guages show the correct pressures, then it may be only the low pressure switch. This is a basic way to start looking for your problem.
If I can be of any more help, let me know.
JTHVETTE
go to your accumalator(aluminum cylinder on passenger's side near firewall) and disconnect the plug on the low pressure switch. I use a paper clip or a piece of wire to jump this plug out to see if the clutch will engage. If it does, then you probably are low on freon or a bad switch. If you are low on freon, add as needed. You will need a set of a/c guages and a leak detector(sniffer). If the guages show the correct pressures, then it may be only the low pressure switch. This is a basic way to start looking for your problem.
If I can be of any more help, let me know.
JTHVETTE
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by cresus
Ok...I'll try joining the pressure terminals. I have a gauge and it shows 30psi. Thanks everyone. I'll let you know how it turns out.
Zeke
Zeke
Thread Starter
Racer
Joined: May 2003
Posts: 348
Likes: 1
From: Hermosa Beach, CA
Sorry this is the low side by the way. It's running but the A/C doesn't cycle so the high side is the same. It's an automatic climate control. According to my manual you can check the automatic control shows a code if the system is low on freon which it hasn't. Is there a way to test the high pressure switch? Can I just disconnect it to see if it's ok? It just doesn't blow cold. I've turned the compressor over by hand so it hasn't seized up. Thanks everyone.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
mate, i reckon its a sticky presure switch somewhere.If it was engaging the compressor then it would be something to do with the flaps that control the temp with the heater core and evaporator core,this is controlled by vacuum lines as far as i know,and these can perish,come off,get blocked etc.Really hard to say without seeying it,and being in Australia i dont think i will ever see it,but id go with the presure switches,and check both cause it could be either one. If it were me, id have the system flushed and refilled, cause it probably hasnt ever been done since the car was new.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
if you do go with flush,get the UV dye put in, it wont harm anything,cause its an oil anyway. And some leaks might only be pin hole size which you wouldnt see any other way. The sniffer really only gives an educated guess at where a leak "might" be, the dye will show you exactly where it is,and you know straight away what you will need to replace. When the A/C system sits without use for a while, it can also absorb moisture, which is another good reason to go with a flush.
Melting Slicks
Joined: Feb 1999
Posts: 3,261
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From: sonoma ca
Racer
Joined: Oct 2003
Posts: 429
Likes: 0
From: Plains Ga.
A/C not cooling?
Originally Posted by Casethecorvetteman
if you do go with flush,get the UV dye put in, it wont harm anything,cause its an oil anyway. And some leaks might only be pin hole size which you wouldnt see any other way. The sniffer really only gives an educated guess at where a leak "might" be, the dye will show you exactly where it is,and you know straight away what you will need to replace. When the A/C system sits without use for a while, it can also absorb moisture, which is another good reason to go with a flush.
A sniffer will find leaks where you cannot see. I use them quite often.
JTHVETTE
