Where are the high side and low side refrigerant ports?

Look close to the fire-wall in the area under the driver's-side windshield wiper. If you're adding refrigerant with the system from an auto-parts store, the fitting on the hose will not fit the high-side port, only the low-side port. Also, there should be a black plastic cap on the low-side port.

Verify ambient temperature is above 65 degrees F.

1. Safety> - safety glasses, long sleeves and gloves, (exposure to refrigerant can cause frostbite).

2. Attach hoses to manifold> assembly, (hi, lo, and fill).

3. Remove caps from service ports, (Low press. Larger tube from evaporator to accumulator - passenger side over fender well; High Pressure - smaller tube from evaporator along firewall towards driver's side). Verify service> ports are clean.

4. Attach low press. and high press hoses to proper service ports.

5. Start car>, reset low refrig code, and turn ac on high and fan on high.

6. Read gauges and compare with chart provided with gauge set.

7. If low and high press readings are both low, then system needs recharge.

8. To recharge, attach fill hose to can of R134a and slowly open low press valve>, (NOT HIGH PRESS VALVE), until low press side reads 40 psi.

9. When flow stops and pressures stabilize close valves> and disconnect manifold from service ports and refrigerant can. Replace service port caps.

Is it possible you hooked up to the factory service port on the high side instead of the low side port ?
Can you hook up a set of gauges to both high and low ports ?

CHECK REFRIGERANT CHARGE. USING A MANIFOLD GAUGE SET. HOOK MANIFOLD GAUGE SET TO LOW PRESSURE PORT AND HIGH PRESSURE SIDE PORT. LOW SIDE PRESSURE SIDE SHOULD HAVE 25 - 36 PSI AND HIGH PRESSURE SIDE SHOULD BE 178 - 237 PSI. IF LOW SIDE PRESSURE SIDE READ BELOW 20 PSI THE LOW PRESSURE SWITCH WILL NOT TURN ON THE AC COMPRESSOR CLUTCH NEED TO ADD LITTLE MORE REFRIGERANT. IF REFRIGERANT LEVEL CORRECT CHECK AC COMPRESSOR FUSE AND RELAY.IF POWER GOING TO AC COMPRESSOR CLUTCH YOUR COMPRESSOR CLUTCH HAS OPEN WINDING. AC COMPRESSOR CLUTCH NEED REPLACING.

The newer cars have 2 ports. The large port which is the high side and small port, low side. The kit you buy to refill the air cond will fit only one of the ports and that's the small port. You don't want to hook up on the high side so, this is why ports are sized and the gauge will only fit one. The low side should be near the evaporator or on the evaporator.

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

Easy. find the compressor. The larger hose attaching to the compressor is the "suction" side. This is where you install the refrigerant.

The smaller hose, whether rubber or metal as it travels to the passenger compartment, is the high pressure side.

After installing refrigerant and as the compressor is running, the larger hose will feel cool and the pressure side will feel hot.

Basic AC system consists of Compressor pump (on engine), Condenser (front grill with radiator) and Evaporator (Firewall). Pump has two ports output (high pressure) and return (low pressure). Follow lines from pump. High side is usually between pump and condenser. Follow lines and find second port this will be low side (refill) port. Paint or replace port caps (red high, blue low). Also, refrigerant in system determines port size (R12 or R34).

Should be reciever/drier pass side undehood.will be fitting with black cap their.Attach to port with charge line .Must have engine running and compressor on.

if you notice the size of them , the bigger port is the high side , and the smaller of the 2 is the low side , you will add freon to the smaller port - the low / suction side .