Frustratingly inconsistent AC system
#1
07-12-2019 | 09:05 PM
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Rock Crawling
Joined: Nov 2018
Posts: 303
Likes: 65
Frustratingly inconsistent AC system
So I've reached the point in attempting to diagnose what's wrong with my AC system where I'm about to start pulling my hair out, and I was hoping you fine folks could provide some assistance.
In the interest of completeness, here is the full sequence of events:
Phase 1: System would not hold pressure. Put a can of Red Angel in it before tearing apart the dashboard to check the evaporator, and it seems to have fixed it... for now, anyway.
Phase 2: System would start cold, and then warm up. Found out that I had overcharged the system and allowed moisture in, so evacuated the system, replaced the receiver/dryer, and refilled. Also found out the condenser fan motor was broken, so replaced that.Ven
Phase 3 (right now): Vent temperature was 50 degrees at the beginning and going down the highway, then rose into the 60s once I got off the highway and into stop and go traffic. On the way home, however, there were no problems, and the vent temperature was around 45.
I cannot tell whether the evaporator is freezing up or the condenser is blocked, but the AC appears to only have problems at low speeds and after the system has been running for a while. Does anyone have any idea what this could be?
In the interest of completeness, here is the full sequence of events:
Phase 1: System would not hold pressure. Put a can of Red Angel in it before tearing apart the dashboard to check the evaporator, and it seems to have fixed it... for now, anyway.
Phase 2: System would start cold, and then warm up. Found out that I had overcharged the system and allowed moisture in, so evacuated the system, replaced the receiver/dryer, and refilled. Also found out the condenser fan motor was broken, so replaced that.Ven
Phase 3 (right now): Vent temperature was 50 degrees at the beginning and going down the highway, then rose into the 60s once I got off the highway and into stop and go traffic. On the way home, however, there were no problems, and the vent temperature was around 45.
I cannot tell whether the evaporator is freezing up or the condenser is blocked, but the AC appears to only have problems at low speeds and after the system has been running for a while. Does anyone have any idea what this could be?
#2
07-14-2019 | 10:20 AM
TReK
Joined: May 2011
Posts: 2,758
Likes: 394
From: kitchener, canada
So I've reached the point in attempting to diagnose what's wrong with my AC system where I'm about to start pulling my hair out, and I was hoping you fine folks could provide some assistance.
In the interest of completeness, here is the full sequence of events:
Phase 1: System would not hold pressure. Put a can of Red Angel in it before tearing apart the dashboard to check the evaporator, and it seems to have fixed it... for now, anyway.
Phase 2: System would start cold, and then warm up. Found out that I had overcharged the system and allowed moisture in, so evacuated the system, replaced the receiver/dryer, and refilled. Also found out the condenser fan motor was broken, so replaced that.Ven
Phase 3 (right now): Vent temperature was 50 degrees at the beginning and going down the highway, then rose into the 60s once I got off the highway and into stop and go traffic. On the way home, however, there were no problems, and the vent temperature was around 45.
I cannot tell whether the evaporator is freezing up or the condenser is blocked, but the AC appears to only have problems at low speeds and after the system has been running for a while. Does anyone have any idea what this could be?
In the interest of completeness, here is the full sequence of events:
Phase 1: System would not hold pressure. Put a can of Red Angel in it before tearing apart the dashboard to check the evaporator, and it seems to have fixed it... for now, anyway.
Phase 2: System would start cold, and then warm up. Found out that I had overcharged the system and allowed moisture in, so evacuated the system, replaced the receiver/dryer, and refilled. Also found out the condenser fan motor was broken, so replaced that.Ven
Phase 3 (right now): Vent temperature was 50 degrees at the beginning and going down the highway, then rose into the 60s once I got off the highway and into stop and go traffic. On the way home, however, there were no problems, and the vent temperature was around 45.
I cannot tell whether the evaporator is freezing up or the condenser is blocked, but the AC appears to only have problems at low speeds and after the system has been running for a while. Does anyone have any idea what this could be?
Pressure test system with nitrogen
evacuate and weigh in charge
your refrigerant charge is probably not right
#5
07-14-2019 | 11:39 AM
Rock Crawling
Joined: Nov 2017
Posts: 450
Likes: 81
From: Kailua Kona, HI
Take your car to a mechanic with a proper AC machine.
You evacuated the system? How? Did you pull a vacuum on it before recharging? How? I doubt you have access to tbe right machines to do this.
Parts store refrigerant in a can does NOT fix AC systems. They call for an exact amount of charge, and tossing some more in very rarely helps, regardless of what the counter jockeys tell you
Invest the $150 and have a professional do it.
You evacuated the system? How? Did you pull a vacuum on it before recharging? How? I doubt you have access to tbe right machines to do this.
Parts store refrigerant in a can does NOT fix AC systems. They call for an exact amount of charge, and tossing some more in very rarely helps, regardless of what the counter jockeys tell you
Invest the $150 and have a professional do it.
#6
07-14-2019 | 05:30 PM
Thread Starter
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Rock Crawling
Joined: Nov 2018
Posts: 303
Likes: 65
Take your car to a mechanic with a proper AC machine.
You evacuated the system? How? Did you pull a vacuum on it before recharging? How? I doubt you have access to tbe right machines to do this.
Parts store refrigerant in a can does NOT fix AC systems. They call for an exact amount of charge, and tossing some more in very rarely helps, regardless of what the counter jockeys tell you
Invest the $150 and have a professional do it.
You evacuated the system? How? Did you pull a vacuum on it before recharging? How? I doubt you have access to tbe right machines to do this.
Parts store refrigerant in a can does NOT fix AC systems. They call for an exact amount of charge, and tossing some more in very rarely helps, regardless of what the counter jockeys tell you
Invest the $150 and have a professional do it.
That's a fair question. To answer, yes, I pulled 30 mm Hg for about 40 minutes, then left it for an hour to make sure it could hold vacuum, which it does. I also added refrigerant by weight rather than pressure. It's probably not 700g, but it's likely within the 25g band specified by the RAVE manual. I'll probably end up taking it to a professional anyway, but I'd rather figure out if there's some obvious answer first.
To answer the other question, no, I don't have rear air.
#9
07-15-2019 | 08:22 PM
Rock Crawling
Joined: Nov 2017
Posts: 450
Likes: 81
From: Kailua Kona, HI
That's a fair question. To answer, yes, I pulled 30 mm Hg for about 40 minutes, then left it for an hour to make sure it could hold vacuum, which it does. I also added refrigerant by weight rather than pressure. It's probably not 700g, but it's likely within the 25g band specified by the RAVE manual. I'll probably end up taking it to a professional anyway, but I'd rather figure out if there's some obvious answer first.
To answer the other question, no, I don't have rear air.
To answer the other question, no, I don't have rear air.
#10
07-15-2019 | 08:27 PM
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Rock Crawling
Joined: Nov 2018
Posts: 303
Likes: 65
I had to compensate for refrigerant left in the hoses. The RAVE manual has a calculation for that, but it's not perfectly precise; hence why there's some leeway in the amount of refrigerant used.