1980 Air Conditioner
Thread Starter
Racer
Joined: Apr 2022
Posts: 276
Likes: 290
From: in St. Louis
1980 Air Conditioner
We’re taking the Vette on a road trip from St. Louis to Lexington and Bowling Green Kentucky. When I turn on the A/C (norm or max) it blasts strong and cold through the registers. Over time (about 20 mins) the airflow slowly decreases, but I can hear the blower running full blast. If I turn the system off for 1 or 2 minutes it repeats the process, blowing strong and cold then decreases.
My thought is the air control door opens with vacuum and it slowly leaks down closing the door. Is my thinking on track?
Thanks
jim
My thought is the air control door opens with vacuum and it slowly leaks down closing the door. Is my thinking on track?
Thanks
jim
Race Director
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From: Shamong, NJ
Le Mans Master
Joined: Mar 2004
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From: Little Rock AR
Just a guess - Lower refrigerant pressure makes the evaporator temp decrease. If it gets so low that the suction temp falls below the freezing point, your evaporator coil will block up with ice. No air blows thru the ice. Wait a while and the ice melts.
If the air temp gets colder (and damper) as you drive until the air stops flowing, this could be the problem. Leaks causing low refrigerant charge maybe?
If the air temp gets colder (and damper) as you drive until the air stops flowing, this could be the problem. Leaks causing low refrigerant charge maybe?
Thread Starter
Racer
Joined: Apr 2022
Posts: 276
Likes: 290
From: in St. Louis
Just a guess - Lower refrigerant pressure makes the evaporator temp decrease. If it gets so low that the suction temp falls below the freezing point, your evaporator coil will block up with ice. No air blows thru the ice. Wait a while and the ice melts.
If the air temp gets colder (and damper) as you drive until the air stops flowing, this could be the problem. Leaks causing low refrigerant charge maybe?
If the air temp gets colder (and damper) as you drive until the air stops flowing, this could be the problem. Leaks causing low refrigerant charge maybe?
I’ve considered that. But only after one minute after turning the system off the air flows strong again so I don’t think the evaporator is blocked with ice.
Thread Starter
Racer
Joined: Apr 2022
Posts: 276
Likes: 290
From: in St. Louis
Here’s a shout out to @stingr69 for diagnosing my issue. My mechanic found my refrigerant low and leaks in the high and low side service ports. I drove the car for an hour after picking it up and the A/C blew strong the whole time.
