More than likely a blockage in the evapotartor drain that come out of the bottom of the inside a/c unit in the car. The hose gets clogged up with stuff. If you can get underneath there and stick something stiff but soft(won't puncture anything) in it, if water come running out, you have probably fixed your problem. If that doesn't do it, a low charge could cause it also but I doubt it.
low side of a/c is the larger diameter line it the smaller fitting(charge side) vs. high side is your smaller line larger fitting
The low side is always the big line on the a/c system. The little line is the high side.
I am assuming you are talking about the A/C. From the compressor, locate the large black hose comming from the A/C compressor. It goes into a small hard line, the valve on this hard line is the low side service port. The hose the comes from the A/C condencer is the high side service port.
The low side hose is the larger one coming from the a/c compressor to the a/c compressor... The high pressure charging valve is located either on the high pressure line or the muffler, and the low pressure charging valve is located either on the accumulator or low pressure line.
if you are referring to the a/c lines just trace the biggest line from the back of your compressor to the fitting and that's your low side port.
The small connector in the a/c line is the low port and the big connector is the high port side ...
on the biggest line coming from the a/c compressor.
As with any car A/C system, the low side is the larger diameter line, the high side is smaller diameter. During operation, the high side line gets hot, and the low side gets cool or cold and is usually covered with condensation.
the low pressure line will be the cold line if the ac is running or if you find the two ac coupler fittings, the smaller of the two is the low pressure side. typically has a blue cap or an L on the cap
Its in the biggest line trace it from your a/c compressor.
You can find the low side on the a/c compressor or on the low side suction hose...........
Follow the larger line from the a/c compressor