Automotive Air Conditioning Information Forum (Archives)

SooBoy on Tue July 10, 2012 2:26 PM

Year: 2007
Make: Dodge
Model: Grand Caravan
Engine Size: 3.3
Refrigerant Type: 134a
Ambient Temp: 75
Pressure Low: 0
Pressure High: 0
Country of Origin: Canada

Hello: I have a system that doesn't work. The cooling fan will not come on and when I hook up my guages both sides read 0. Where do I begin? I've checked the fuses in the PCM and they seem fine. Can't tell from looking if the relay works. Can't see any problems with the fan wires (not rusted, broken). No obvious signs of leakeage. Will the pressures read if the fan isn't working? If both sides show 0 does that mean I'm completely empty? If so, will a recharge restart the fan? Thanks for your time on this people.

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John R. Wilson

mk378 on Tue July 10, 2012 7:34 PM

There's a major leak. If you just recharge it will leak out again -- in seconds, minutes, days, maybe a week if you're lucky.

System is designed to shut down with zero pressure to protect the compressor.

Edited: Tue July 10, 2012 at 7:35 PM by mk378

SooBoy on Tue July 10, 2012 8:08 PM

Thanks very much. Can I pressurize the system with air to look for the leak? Or should I add some refrigerant and use my u/v light and "sniffer"? Thanks for your help on this.

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John R. Wilson

mk378 on Tue July 10, 2012 10:48 PM

With an electronic "sniffer", charge a very small amount of R134a with the engine stopped, to get about 10 psi, and start sniffing around. Watch the gauge to see how fast it leaks out. If it seems to be holding you may need more pressure.

SooBoy on Wed July 11, 2012 3:50 PM

Thanks for the guidance. I put 10psi in and checked as quickly as I could with the "sniffer" but it went to 0 in about 3 minutes flat. Any suggestions where to look for a bleed this big? Also, when I check with my u/v light, do I need the yellow glasses, or will the dye show up clearly? Thanks for your help.

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John R. Wilson

JJM on Wed July 11, 2012 8:46 PM

With a leak that big, save your money and pressurize it with air and you can probably hear where it's leaking from. Old fashioned soapy solution on the components will probablly work.

If I had to guess, a rubber line is blown open somewhere, condenser has a hole, or fitting is very loose. Doubt a shaft seal will leak that bad on an '07 vehicle... unless it has like 300,000 miles or something.

Joe

mk378 on Wed July 11, 2012 9:00 PM

Damage to the condenser from rocks, corrosion, etc. is a common cause of a sudden large leak. Look in the service port to see if the system had dye from the factory. The system needs to be charged up fully and running for dye to move around and escape from leaks. The yellow glasses aren't essential (they are just blue blocking glasses that you can buy anywhere for shooting or driving). It always works better to wait for darkness before using a UV light.

Edited: Wed July 11, 2012 at 9:04 PM by mk378