Air Conditioning
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Joined: Oct 1999
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Air Conditioning
Hello Everyone.
This is probably an beaten to death question but I'm having air conditioning problems in my 84. The compressor clutch is fine, runs great. Gas is fully charged and yet no cool air blows. The car does sit quite a bit and I'm thinking that perhaps a valve is stuck. Any ideas?
Thanks.
This is probably an beaten to death question but I'm having air conditioning problems in my 84. The compressor clutch is fine, runs great. Gas is fully charged and yet no cool air blows. The car does sit quite a bit and I'm thinking that perhaps a valve is stuck. Any ideas?
Thanks.
Melting Slicks
Joined: Jan 2014
Posts: 2,185
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From: Lunenburg MA
How do you know it's fully charged? It could be a bad high/low pressure switch. If you're sure it's fully charged try applying ground and +12 directly to the clutch. It should engage and it should blow cold. If that works, try shorting the switches one at a time.
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The local garage has a set of gages they use in air conditioning and they read that the system is fully charged. The compressor kicks in just fine, no problems there. It will just not blow cold and the garage is at a loss of why.
Melting Slicks
Joined: Jan 2014
Posts: 2,185
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From: Lunenburg MA
You need a different garage. It's not all that complicated if you understand the basics and have the tools.
Burning Brakes
Joined: Oct 2001
Posts: 911
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From: TN
My 1985's GM service manual/book only mentions using your hands to feel the air conditioning pipes and I believe the accumulator to check and see if it needs more R12.
Safety Car
Joined: Sep 2004
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From: Mission Viejo CA
Last edited by Hot Rod Roy; Jul 16, 2014 at 12:42 AM.
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Fan works fine at all speeds. Lines are cold to the touch, compressor works fine and comes on when AC is switched on, no delays. No cold air comes out the vents. What is a FSM? "Front Side Mirror'??????
Melting Slicks
Joined: Jan 2014
Posts: 2,185
Likes: 381
From: Lunenburg MA
Factory Service Manual. If the evaporator is indeed cold and the blower is running, then air is not being directed through it. The FSM would help you (or your garage) to troubleshoot it.
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Burning Brakes
Joined: Apr 2009
Posts: 1,185
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From: Charlotte Michigan
Temperature door may not be working. May have a bad vacuum line, dry rotted from age. You need the factory gm fsm to work on any corvette! Without it is to be ignorant, unless you have lots of money to spend and throwaway!
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
If manual ac its a control cable or temp door issue.
For ATC: If blower air exits the defroster vents only: The vacuum supply has been lost or there is a control head issue.
If the system changes modes as designed: Either no vacuum to the temp door motor, the temp door motor has failed, temp door is stuck or there is a control head issue.
Good luck.
For ATC: If blower air exits the defroster vents only: The vacuum supply has been lost or there is a control head issue.
If the system changes modes as designed: Either no vacuum to the temp door motor, the temp door motor has failed, temp door is stuck or there is a control head issue.
Good luck.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
There is a cable that connects the HOT - COLD lever to the temp door lever. Check that connection and make sure everything is working.
You can also take out the blower motor resistor module from the evaporator housing and see if the blend door is moving from the full cold to the full hot position. It's the rusty part in this picture (full cold position):
You can also take out the blower motor resistor module from the evaporator housing and see if the blend door is moving from the full cold to the full hot position. It's the rusty part in this picture (full cold position):