Airconditioning not working
Thread Starter
Instructor
Joined: Dec 2005
Posts: 101
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Airconditioning not working
I have a 94 LT1
The air always worked & was ice cold. I haven't been using it for awhile (didn't have a need to) & when I checked it today....nothing...notta....zero.
It blows warm air. I can hear the a/c clutch engage...but thats it.
I also just had a problem where I found a bare wire in the pass. door because when someone took it apart before...they didn't keep it out of the way of the window when it went down. I fixed it...but never blew any fuses. I'm not sure this is related so I checked all the fuses in the car & under the hood & they were all AOK.
Couple questions.....
1 - what would be an average cost to diag & repair the a/c unit?
2 - when I turn on the a/c...does the secondary fans come on automatically or only when the temp is a specific degree?
Any advice will be cool (no pun intended). All the years experience I have with cars...I never had to do anything with a/c before. Most of the time...I just said 'screw it'. I want to fix this...but don't want to do it myself.
The air always worked & was ice cold. I haven't been using it for awhile (didn't have a need to) & when I checked it today....nothing...notta....zero.
It blows warm air. I can hear the a/c clutch engage...but thats it.
I also just had a problem where I found a bare wire in the pass. door because when someone took it apart before...they didn't keep it out of the way of the window when it went down. I fixed it...but never blew any fuses. I'm not sure this is related so I checked all the fuses in the car & under the hood & they were all AOK.
Couple questions.....
1 - what would be an average cost to diag & repair the a/c unit?
2 - when I turn on the a/c...does the secondary fans come on automatically or only when the temp is a specific degree?
Any advice will be cool (no pun intended). All the years experience I have with cars...I never had to do anything with a/c before. Most of the time...I just said 'screw it'. I want to fix this...but don't want to do it myself.
Pro
Joined: Feb 2005
Posts: 560
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From: Hamilton New Jersey
you say you can hear the clutch engaging.. have you looked to see if its engaged while the ac is on? If it is does is it cycling on and off fast or anything odd? If the clutch stays engauged I'd lean towards a problem with the blend air door or what ever's controlling its position. If the clutch is cycling on and off rapidly its most likely a low pressure/high pressure situation that could be caused by a multitude of things.. or a bad pressure switch.. let us know on the clutch..
Le Mans Master
Joined: Jul 2007
Posts: 5,356
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From: No HOA, New Hampshire
Cruise-In X Veteran
St. Jude Donor '09
you say you can hear the clutch engaging.. have you looked to see if its engaged while the ac is on? If it is does is it cycling on and off fast or anything odd? If the clutch stays engauged I'd lean towards a problem with the blend air door or what ever's controlling its position. If the clutch is cycling on and off rapidly its most likely a low pressure/high pressure situation that could be caused by a multitude of things.. or a bad pressure switch.. let us know on the clutch..
Thread Starter
Instructor
Joined: Dec 2005
Posts: 101
Likes: 0
you say you can hear the clutch engaging.. have you looked to see if its engaged while the ac is on? If it is does is it cycling on and off fast or anything odd? If the clutch stays engauged I'd lean towards a problem with the blend air door or what ever's controlling its position. If the clutch is cycling on and off rapidly its most likely a low pressure/high pressure situation that could be caused by a multitude of things.. or a bad pressure switch.. let us know on the clutch..
When I do....it seems like it cycles or makes it's normal clutch noises every 5-6 seconds.
Pro
Joined: Feb 2005
Posts: 560
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From: Hamilton New Jersey
If its cycling that fast it's most likely due to either high or low pressure in the system, or a faulty switch. Manifold gauges would be helpful. If you can get us some pressure readings we can probably talk you through the repair 
Thread Starter
Instructor
Joined: Dec 2005
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well, I don't have any gauges for that....
any idea what this would cost or what an air conditioning repair would cost?
Pro
Joined: Feb 2005
Posts: 560
Likes: 0
From: Hamilton New Jersey
your guess is as good as mine, it all depends on what the actual problem is. A decent set of gauges can be had for about $40-70 at your local parts store. It's most likely low pressure due to a leak. Gauges would help verify that. If it is a leak you should be able to track it down by looking for a "wet" spot, when a/c systems leak they also leak oil which will leave a mark where the leak is (your system may also have a/c leak dye in it which can be easily seen by use of a uv light). Small leaks can be hard to find. Thats all assuming it's due to low pressure though. It's best to get pressure readings than go from there.
Thread Starter
Instructor
Joined: Dec 2005
Posts: 101
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your guess is as good as mine, it all depends on what the actual problem is. A decent set of gauges can be had for about $40-70 at your local parts store. It's most likely low pressure due to a leak. Gauges would help verify that. If it is a leak you should be able to track it down by looking for a "wet" spot, when a/c systems leak they also leak oil which will leave a mark where the leak is (your system may also have a/c leak dye in it which can be easily seen by use of a uv light). Small leaks can be hard to find. Thats all assuming it's due to low pressure though. It's best to get pressure readings than go from there.
Thanks
I was surprised how it suddenly stopped working. I just don't know how expesive all this can be. I guess I'll just have to take it in somewhere.
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Drifting
Joined: Feb 2003
Posts: 1,614
Likes: 163
From: Davis CA
You can purchase a gauge with the 134. Very cheap and easy to use. You're bound to be low. Please note that you read pressure while the compressor is engaged. I'll bet that 1 to 2 cans puts you back where you want to be.
By the way, I had a heater core leak and bypassed the core. My AC has never been colder. It is very cold even here in the central valley where we often go over 100. Be sure that your valve is working.
By the way, I had a heater core leak and bypassed the core. My AC has never been colder. It is very cold even here in the central valley where we often go over 100. Be sure that your valve is working.
Instructor
Joined: Dec 2004
Posts: 231
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1) lift hood and turn on a/c to lowest control.
2) start car. you should hear the a/c compressor clutch click in.
3) if you don't, could be low on refrigerant or bad pressure switches in a/c line(s).
4). if you hear the clutch kick in and it clicks in and out many times (but not rapidly), you may be low on refrigerant.
5) connect ohm meter to the terminals on the ac clutch and it should register continuity. if it doesn't, clutch is bad.
5) if continuity is ok, switch to voltage scale and (with ac on) see if you have voltage at the connector. if ya don't problem lies further back.
2) start car. you should hear the a/c compressor clutch click in.
3) if you don't, could be low on refrigerant or bad pressure switches in a/c line(s).
4). if you hear the clutch kick in and it clicks in and out many times (but not rapidly), you may be low on refrigerant.
5) connect ohm meter to the terminals on the ac clutch and it should register continuity. if it doesn't, clutch is bad.
5) if continuity is ok, switch to voltage scale and (with ac on) see if you have voltage at the connector. if ya don't problem lies further back.
Burning Brakes
Joined: Sep 1999
Posts: 786
Likes: 31
Cruise-In II Veteran
Did you check for any codes? This is the first step I always take for diagnosing HVAC problems. Checking the codes can save a lot of time by possibly isolating the problem area.
http://www.idavette.net/tech/c4diag.htm
http://www.idavette.net/tech/c4diag.htm
Burning Brakes
Joined: Aug 2007
Posts: 792
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From: Austin Tx
With the short cycling most likely you are just low on refrigerant. A shop can add dye and find the leak and put the exact amount of charge on the system. At our shop to find and repair a small leak ( o-ring, access valve, pressure switch) and recharge is about 100.00 to 150.00.
Thread Starter
Instructor
Joined: Dec 2005
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Thanks for all the replies
Not sure if this is related...but I may have a blown head gasket. There's too many signs showing of this. It all just happened. There's the old white smoke from the exhaust tip, funny smell, white goo on the oil cap, heating up quicker than normal....etc..
Not sure if this is related...but I may have a blown head gasket. There's too many signs showing of this. It all just happened. There's the old white smoke from the exhaust tip, funny smell, white goo on the oil cap, heating up quicker than normal....etc..
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Rg951,
one crazy idea. Maybe it is just the pressure switch electrical plug or wire.
On a 94, the pressure switch is in the AC line which is on the passenger side, low, just a few inches above the frame, and almost even in height with the spark plugs.
There is a small 2-wire plug connected to it.
Might be worth just checking the wiring and that the plug doesn't have corrosion on/in it.
one crazy idea. Maybe it is just the pressure switch electrical plug or wire.
On a 94, the pressure switch is in the AC line which is on the passenger side, low, just a few inches above the frame, and almost even in height with the spark plugs.
There is a small 2-wire plug connected to it.
Might be worth just checking the wiring and that the plug doesn't have corrosion on/in it.
Intermediate
Joined: Oct 2007
Posts: 28
Likes: 0
i had a similar problem on my 91 vette after having my comprseeor replaced was just blowing hot air
had to reset the electronic climate control
by pulling fuse 1 and 17 for 15 sec this reset it
cold air started coming in
was told loss of power can cause the climate control to mess up and every once in awhile ya have to reset it
had to reset the electronic climate control
by pulling fuse 1 and 17 for 15 sec this reset it
cold air started coming in
was told loss of power can cause the climate control to mess up and every once in awhile ya have to reset it
Last edited by c4vic; Oct 14, 2007 at 06:56 AM.
Racer
Joined: Nov 2006
Posts: 322
Likes: 1
From: Muskego Wisconsin
JCWhitney sells R134a and the the adapter to fill. The adapter has a gauge. The instructions are not very accurate but if you can get past the instructions it will work well for you. You are probably 1 can or 1 pound low on freon. That is why it suddnly stopped working...just a slow leak.