2002 Pontiac Ram Air Trans Am ac is not cooling properly

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Al9
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby Al9 » Sat Sep 05, 2020 8:31 am

PAG Blue or PAG 125 are the commercial denominations of possible equivalents to the oil originally featured in these compressors, a slightly thinner PAG 125 oil. But PAG 150 is basically the same thing.
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bohica2xo
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby bohica2xo » Sat Sep 05, 2020 10:35 am

Sorry Danny.

After a19 starts clogging up a thread with useless junk I just scroll to the end - where I see pressures as high as 400 psi. I missed the part where you sprayed the condenser.

You say the fan blows well. But what is well? is it 75% of what it did when brand new? The only metric we have for older cars fans is current draw and cooling. With worn brushes, current drops and air flow drops. We chased this on the old board, it went about 8 pages with a Ford Edge I believe. New fan brought the high side down to the proper range.

I am NOT saying that the fan motors are bad - other things like clogged fins & debris in the heat exchanger stack can cause the same issue. As can missing air dams and seals - if the fans are pulling air from the edges of the stack, the air bypasses the condenser.

Once you get the proper charge level in the system, and are sure your heat exchanger air path is clean & clear, you can further evaluate the condition of the fan motors.
Dougflas
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby Dougflas » Sat Sep 05, 2020 11:32 am

That machine you posted does not reclaim. It is only for recovery. You would have to use new refrigerant if you used that machine. And as mentioned, it does not separate refrigerant from oil.
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Sun Sep 06, 2020 12:22 pm

bohica2xo wrote:Sorry Danny.

After a19 starts clogging up a thread with useless junk I just scroll to the end - where I see pressures as high as 400 psi. I missed the part where you sprayed the condenser.

You say the fan blows well. But what is well? is it 75% of what it did when brand new? The only metric we have for older cars fans is current draw and cooling. With worn brushes, current drops and air flow drops. We chased this on the old board, it went about 8 pages with a Ford Edge I believe. New fan brought the high side down to the proper range.

I am NOT saying that the fan motors are bad - other things like clogged fins & debris in the heat exchanger stack can cause the same issue. As can missing air dams and seals - if the fans are pulling air from the edges of the stack, the air bypasses the condenser.

Once you get the proper charge level in the system, and are sure your heat exchanger air path is clean & clear, you can further evaluate the condition of the fan motors.


bohica, the only thing that I have to "tell" me that the fan(s) were running on high is the change in sound when they were commanded to go to high. The sound might have only come from one fan. I assumed both but I really don't know for sure at this point. Can you elaborate on the method to measure current draw? I'm not real good with electrical stuff and I'm pretty sure my DOV meter is only good for 10amps.

I'll look extra close for loss of air dams and seals. I spent a lot of time examining the condenser for leaks but nothing missing jumped out at me. I'll look again over the course of the next week. I'll be taking things apart to look in between the condenser and the radiator. I'd love to find a "smoking gun" there!
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Sun Sep 06, 2020 12:26 pm

Dougflas wrote:That machine you posted does not reclaim. It is only for recovery. You would have to use new refrigerant if you used that machine. And as mentioned, it does not separate refrigerant from oil.


Yes, only a recovery machine. I've also looked at the Mastercool 69000 which does separate the oil. More money but it is assembled in the USA. Undoubtedly full of china parts like everything else. I spoke on the phone with Mastercool last week and they did confirm that I won't be able to reuse the refrigerant recovered with the 69000 because it isn't a reclaiming machine.

I'm planning on using virgin R134a.
B52bombardier1
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby B52bombardier1 » Sun Sep 06, 2020 1:29 pm

Do your fans have a wattage number stamped on them somewhere or maybe online somewhere? If yes, we can derive the amps. Maybe, let's say = 240 watts? 20 amps x 12 volts = 240 watts.

A clamp on ammeter can also measure amperage though maybe less accurately.

Rick
1970 Chevrolet El Camino 5.3 L LM7 Truck Engine & 4L60E Transmission
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Sun Sep 06, 2020 2:00 pm

B52, I just did some internet searching to see if I could find a wattage rating for the fans and I came up with nothing. I can look at the fan motors later in the week when I take things apart. Maybe I'll get lucky and there will be something useful on the fan's sticker.
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby bohica2xo » Mon Sep 07, 2020 3:16 pm

That is an ongoing problem with electric fans. No real metrics for the OEM motors, and aftermarket stuff is all over the place.

Usually the difference between ram air & parked cooling is a good indicator. Duct taping the gauge set on the windshield on the passenger side & going for a drive with an observer. Yeah, it sounds crazy, but sometimes you need pressure readings above 50 mph to get solid data.

Fans, whether electric or mechanical, unload at speed. Contrary to internet lore they do not offer a restriction at highway speed. The fans are there for idle to low speed operation.

One of the reasons we ask for a full load test - Doors open, cabin fan on highest speed, engine RPM above 1500. This duplicates a hot drive off from a parking lot after heat soak - like leaving work. This tests the condenser fan airflow, as well as the compressor output at full capacity.

When you inspect the heat exchangers, look at everything. Adding a bit of foam weather stripping to the edge gaps on GM trucks is a common fix to make sure 100% of the airflow goes through, not around.

Manufacturers got more serious about those problems as time goes on. Eventually we will see brushless fan motors with rpm feedback.
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Fri Sep 11, 2020 7:29 pm

This afternoon I finally got around to disassembling the entire Ram Air filter assembly that covers the top of the radiator and condenser. Once it was all apart it was apparent that there was little to no restriction. There was one cellophane cigarette package wrapper caught at the top of the radiator and there is a small amount of debris in the front of the radiator. The backside of the condenser is clean like the front side.

Here are some pictures:

This is the debris on the front of the radiator
https://www.amazon.com/photos/shared/lGryDgEZR3-18sKXkJbxVw.rWiwmyqb0a8Svoc5XAwy2g

Cigarette wrapper!
https://www.amazon.com/photos/shared/c7lGm6OkSbGtu4h80KkQyw.igh_FpbLIXaeoncM6igFyW

Clean backside of the condenser. This is looking toward the front of the car.
https://www.amazon.com/photos/shared/CB0ZvdiMRYWEGMoET_Qd8g.0BumZOWUWBvfa2Wz_PKTWI

All the OEM pieces looked to be in place with nothing missing. If I've got an airflow problem, I don't think it's from any blockage of airflow or airflow bypassing the condenser. It's still to be determined whether or not the fans are pulling air at 100% capacity.
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Fri Sep 11, 2020 7:34 pm

BTW, I did go overboard and buy the bigger Mastercool 69100 recovery machine kit. Tracking information says that it should be here on the 15th of the month.

Once I have time to use it I'll recover the refrigerant in the system, weigh it and let everyone know how much is in there.

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