Air Conditioning intermittent
07-09-2008, 04:05 AM
#16
Racer
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I have some experience here. Certified AC tech.
Do not assume it is anything..That is rule no.1 with AC.
Here is a list of things to test. Look for Ice. I am serious here. Sometimes if you have a restriction in the system, stuck exp. valve or otherwise your system will freeze up. You will need to look at all of the line and the evaporator, and the condenser This prevents the 134-a or R-12 from circulating in the system ad you get warm air from the vents. You can also get intermittent cold air.
The next is the temp switch. This will tell the system to stop and thus turn off the compressor and stop cycling the refrigerant and then you get warm air. This may also be the click you are hearing. The last thing you want to do is open this closed system to the atmosphere. With that you can create more issues, and unless you have a recovery system, a vaccumme system a micrometer and a dozen other specialized tools and parts, avoid it like the plague.
Do not assume it is anything..That is rule no.1 with AC.
Here is a list of things to test. Look for Ice. I am serious here. Sometimes if you have a restriction in the system, stuck exp. valve or otherwise your system will freeze up. You will need to look at all of the line and the evaporator, and the condenser This prevents the 134-a or R-12 from circulating in the system ad you get warm air from the vents. You can also get intermittent cold air.
The next is the temp switch. This will tell the system to stop and thus turn off the compressor and stop cycling the refrigerant and then you get warm air. This may also be the click you are hearing. The last thing you want to do is open this closed system to the atmosphere. With that you can create more issues, and unless you have a recovery system, a vaccumme system a micrometer and a dozen other specialized tools and parts, avoid it like the plague.
07-09-2008, 12:26 PM
#18
Track Day
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Thank you my84-944
I have diagnosed this fairly well I think. I am not an A/C guy but....I've built a few engines in my time. In any case, the system is running great. click or no click the compressor is engaged and I get really cold air. I know the system is tight because I checked the pressure and it still has r-12....probably why it gets so cold. When I hear the click I immediatelty get hot air only for a time....different lengths of time and another click. usually after a bump, brings me my blessedly cold air again. I think Steve hit the problem on the head and provided pictures and how to knowledge. In calling my local garage they know of this problem and concur. So thank you again. I'll be pulling the solenoid this week and check the connections first. If that doesn't do it I'll replace it. Hopefully that will have it taken care of! I'll post back here with the results.
I have diagnosed this fairly well I think. I am not an A/C guy but....I've built a few engines in my time. In any case, the system is running great. click or no click the compressor is engaged and I get really cold air. I know the system is tight because I checked the pressure and it still has r-12....probably why it gets so cold. When I hear the click I immediatelty get hot air only for a time....different lengths of time and another click. usually after a bump, brings me my blessedly cold air again. I think Steve hit the problem on the head and provided pictures and how to knowledge. In calling my local garage they know of this problem and concur. So thank you again. I'll be pulling the solenoid this week and check the connections first. If that doesn't do it I'll replace it. Hopefully that will have it taken care of! I'll post back here with the results.
07-09-2008, 12:36 PM
#19
Hey Man
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Also check for a cracked vacuum hose(s) leading to the climate control unit. Any leak at all can also make the solenoid click like crazy. They can be cracked or loose both inside and outside the firewall.
Last edited by KuHL 951; 07-09-2008 at 06:40 PM.
07-09-2008, 03:38 PM
#20
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My two cents worth...I bet it's bad solder joints in your climate control unit. Hence the "bump". It's probably allowing the heater coolant valve to open producing heated air. An easy way to check...after driving car to normal temperature, park it and feel the two coolant/heater pipes between the glove box and console if both are hot your heat is or has been on. A quick fix is to bypass the vacuum solenoid that controls the heater valve so it's sending vacuum to it constantly keeping the valve closed. The valve itself may be bad, vacuum test it. You were probably getting cool air, then hit a bump and start getting cold air. I just fixed this same problem by replacing my CCU. The old CCU solder joints were floating in flux. The clicking noise I believe to be the two vacuum solenoid valves by the pipes. The "plastic pieces" only control flaps to control air flow direction, foot, dash vents, defrost, & recirculate. Not cool/hot. It also could be a million other things. Good luck.
