I cannot differentiate between the low pressure and high pressure

There are two ports in the air conditioning system of Equinox. One is labelled H for high-pressure and the other one is labelled L for low-pressure. You can recharge your AC through the low-pressure port with a do it yourself AC recharge kit.Shake the canister briefly and release the refrigerant into the system until the recommended pressure has been achieved. Note: See next section for recommended pressure values

it's straight below the high pressure valve about a foot. it's a little stem with a cap on it. it's kind of by the oil flter. i didn't see it the first time i looked either.

Hi,
The low pressure port for recharging is usually the one near the firewall. That line will also go to a cannister and then into the firewall to the evaporator core. The one by the radiator is usually the high pressure side. Your connector will only fit the low pressure (correct) port for filling, as the 2 ports are different sizes.
Please rate this answer! Thanks, Mike

There is two filling ports for A/C - high pressure is biggest diameter-low pressure smallest one.All of them must have black cups.Because I don.t know exactly the model of your VW I can.t dive you proper instruction.If any problem come back with full details for the vehicle.

Hi, determine if your car uses R134 or R12 refrigerant. You will notice screw type connectors on the both the High Pressure Side and Low Pressure Side lines in models using R12 refrigerant. R134 compatible models have quick connect valves on both sides. Models made before 1995 may use the old R12 refrigerant. If this is the case, you must have your Chrysler's air conditioning system retrofitted to use R134 refrigerant. Mixing R12 and R134 refrigerants is dangerous and may cause damage to your vehicle. Check your air conditioning system pressure using an automotive air conditioning pressure gauge. Keep in mind that in order to get an accurate reading, the air conditioner has be turned on the coldest setting with maximum blowing power. Remove the Low Pressure Side port valve cap and set it aside. The location of the port varies, but it is usually in front of the engine block. Attach the refill hose to the port on the Low Pressure Side of the air conditioning system. The Low Pressure Side port is smaller the High Pressure Side port. Because the ports are different sizes, the refill kit hose should fit only on the Low Pressure Side port. Additionally, the High Pressure Side port will usually have a red cap or be marked with an H or the word High Allow the air conditioner to **** the refrigerant out of the can by slowly turning the valve on the refill kit hose. Pay attention to the way you hold the can. Most kits will have you hold the can upright when you recharge the air conditioning system. It may take as long as 10 minutes to empty a single can. Turn the valve to the off position and remove the refill hose from the port. Recap the port before closing the hood. Let the air conditioner stay on for at least 30 minutes. This allows the refrigerant to move throughout the entire system.
Take care

The Low Pressure Side connector will be smaller than the High Pressure Side connector so the refill hose will fit properly only on the Low Pressure Side.
Read more: How to Recharge Air Conditioning with Freon in a Dodge Ram | eHow.com http://www.ehow.com/how_4484569_recharge-air-conditioning-freon-dodge.html#ixzz0uLCDkUE8

Some times they are hard to find.Find the high side line/hose,on the compressor,follow the line until you find the ac high side service port.The small line is the high side,If I can help any further let me know [email protected]

Sounds like the A/C system just needs to be recharged. When was the last time you had this done? Just take it in to your mechanic and he can do it for you and if that's not it for some reason, then he will be able to find the problem but most likely you need more freon added.

Benjamin

low pressure port is smaller than the high pressure side