I'm having a hard time finding the low pressure port on my 2000 ford lightning, i find two ports one directly on the compressor wich if i hook up to with the car off i get a reading of around 70 psi the other the cap doesnt even fit onto and i dont see it directly connected to the ac system this goes through the radiator. i cant find any other ports can any one help me?

 

The high pressure fitting is on the liquid line going to the condenser near the washer fluid reservoir. It will be the bigger of the two fittings. The low pressure fitting is on the accumulator on the passenger's side rear of the engine compartment, under the bulkhead connectors.

 

considering how dangerous it can be for someone without knowledge and experience to charge AC, Save the problems you may risk, INCLUDING DEATH, by spending the $30 to let a real AC mechanic do the job.