Stock C3 AC
Thread Starter
Drifting
Joined: Mar 2004
Posts: 1,873
Likes: 1
From: Savannah Ga
Stock C3 AC
Is it just me or are all C3 AC units only cool just a little?I just had all that evap.condencer stuff replaced on my 82 and it blows cool but not
cold.I've got it in the shop now.The same shop that did the work,they are gonna look it over.It's not leaking but it's not blowing cold.Can this be adjusted.
cold.I've got it in the shop now.The same shop that did the work,they are gonna look it over.It's not leaking but it's not blowing cold.Can this be adjusted.
Instructor
Joined: Dec 2005
Posts: 190
Likes: 0
From: Hot AZ
This is from a previous thread in the C3 Tech/Performance forum on the same subject...
Quote:
Originally Posted by BobzVette
I had the same problem with my 78 since new Then I found out the temperature control lever cable has a white plastic adjustment control about 10-12 inches from the leaver attachment point. It is located on the pass side of the console. What it does is lengthens or shortens the cable to adjust the air diverter in the a/c - heater plenum. Mine wasn't adjusted correctly from the factory and allowed hot air to mix with the outside air. After I adjusted it to make sure the diverter valve was close with the temp lever all the way to cold...no more hot air always blowing Well, that is when its not 100 degrees in AZ anyway. The a/c even works better too! Check it out before you do any of the major surgery you might get lucky
Check this first. It is the easiest and cheapest solution. If your vacuum operated valve is operating correctly, this will fix your problem. If this does not work, I would suggest attaching a vacuum gauge to the vacuum hose attached to the valve (white nylon hose on passenger side of engine compartment). Move the temp control valve to hot, there should be no vacuum. Move it all the way to cold, you should have a vacuum signal. Now, use the adjustment collar to adjust the cable length so that when your temperature control rod is all the way to cold, you have max vacuum. The vacuum signal should drop off as you move the arm to the hot side. It drops off pretty quick so spend some time and get the adjustment right. As you move the arm from cold to hot (slowly), you should hear a hissing sound. That hissing is the valve at the other end of the temp rod cable (located on top of heater core) bleeding off the vacuum signal and opening the valve in the heater core lines.
If you don't hear this hissing, chances are that you do ot have any vacuum in the control system. The C3 will default to a full heat condition (floor vents and open heater valve) when there is no vacuum in the system at all. Consequence of being designed in Detroit I guess.
Quote:
Originally Posted by BobzVette
I had the same problem with my 78 since new Then I found out the temperature control lever cable has a white plastic adjustment control about 10-12 inches from the leaver attachment point. It is located on the pass side of the console. What it does is lengthens or shortens the cable to adjust the air diverter in the a/c - heater plenum. Mine wasn't adjusted correctly from the factory and allowed hot air to mix with the outside air. After I adjusted it to make sure the diverter valve was close with the temp lever all the way to cold...no more hot air always blowing Well, that is when its not 100 degrees in AZ anyway. The a/c even works better too! Check it out before you do any of the major surgery you might get lucky
Check this first. It is the easiest and cheapest solution. If your vacuum operated valve is operating correctly, this will fix your problem. If this does not work, I would suggest attaching a vacuum gauge to the vacuum hose attached to the valve (white nylon hose on passenger side of engine compartment). Move the temp control valve to hot, there should be no vacuum. Move it all the way to cold, you should have a vacuum signal. Now, use the adjustment collar to adjust the cable length so that when your temperature control rod is all the way to cold, you have max vacuum. The vacuum signal should drop off as you move the arm to the hot side. It drops off pretty quick so spend some time and get the adjustment right. As you move the arm from cold to hot (slowly), you should hear a hissing sound. That hissing is the valve at the other end of the temp rod cable (located on top of heater core) bleeding off the vacuum signal and opening the valve in the heater core lines.
If you don't hear this hissing, chances are that you do ot have any vacuum in the control system. The C3 will default to a full heat condition (floor vents and open heater valve) when there is no vacuum in the system at all. Consequence of being designed in Detroit I guess.
