Location of Low pressure AC service port. on 2005 Dodge Durango

Where is the low pressure AC service port? The High pressure is plainly visible, but I can't find the low pressure side.

Asked by for the 2005 Dodge Durango
Man, finding an answer to this question is ridiculous. It's either the can back by the firewall (accumulator) or the line going to the condenser. On mine both have black caps. Cap color does not tell you anything. The refill is supposed to only fit the low side port. May or may not be true. My guess is the one by the firewall since higher pressure has to be cooled off to condense to a liquid again before it boils and sucks in heat energy. I know the "warning" is justified but man, the refills are sold in every auto parts store around. They also have gauges and directions. People are going to be doing this so warning them not to is not help. How about just a correct answer. Here's a pic of the area

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I'm not sure where it is, but I want to warn against adding refrigerant to the system unless you're 100% sure it is low and you won't overfill it. Doing so can cause major damage, so be very careful. See this article about the dangers of doing this: