AC is intermittent, hot and cold.can it be a condenser

The air conditioning system takes refrigerant gas, passes it through a compressor which changes it into a liquid, sends it through liquid lines to the evaporator core behind the dash, where the fan blows through the icy cold evaporator giving you cool air inside the car. The process also takes moisture out of the air and dehumidifies the interior of the vehicle, releasing water as a byproduct under the vehicle. The liquid warms and changes back into a gas, passing through the condenser to cool it down again so it can again become a liquid as it reaches the compressor...and it all goes around again in a continuous cycle. I mention this to help explain what you are looking for. "It doesn't look like it is low on coolant" -- how could you see this? There's no way to tell until you hook up a set of gauges and test for system pressure. "A part by the belt does seem to move" -- what part do you mean? Way too hard to guess what you are speaking of? The condenser is the set of tubes concealed by fins that sits in front of the radiator -- kind of looks like a thinner radiator itself. If there is a restriction of air flow, or the condenser fan is not working, it can definitely adversely affect air conditioning operation, as the refrigerant gas may not be cooling enough as it reaches the compressor again to recycle through the system. A condenser is not a moving part...it's tubes with fins that refrigerant gas passes through. All this to say -- you need a professional diagnosis from a technician with a certification to handle refrigerants, good refrigerant handling equipment, a set of gauges, the ability to test electrical power of the air condition system, the compressor clutch and coil, the cycle switch.

A faulty condenser isn't the first thing that jumps into mind for intermittent hot and cold. Not saying it's not the issue, but It's not a lot of information to go on. Unfortunately, you're going to need to just have It looked at by a professional. There are so many things it could be to speculate. A free performance check would be great starting point. Just knowing the pressures and temps would enough to know if you need a recharge or further diagnostics.

It is possible but not probable. Leak? You sure it's not low onfreon?