My ac in my truck has worked off & on since i recharged it. When it does cool, it will freeze you out . . When it doesn't cool i can see refrigerant flowing in the sight glass but the compressor does not load the engine at all (yes it runs). Any ideas what's wrong??

 

When it's not cooling how do the high and low side pressures look ?

The low pressure line out of the expansion valve get cold and the high pressure line into the condenser get hot ?

Did you replace the expansion valve ?

Did you have a compressor failure in the past ?

Of course the compressor clutch is engaging so I won't even ask

 

Ok, here goes . .
I have no gauges . . .
the lines do not get hot or cold . .
yes clutch is engaging . .
the compressor failed once when dad had the truck . . .
& no i haven't replaced the metering block . . .

 

Gauges even cheap harbor freight ones are good. Or in my case borrowed from a bud who is a tool ho who has everything and never used them LOL

I asked if compressor had failed as if you didn't replace condenser, expansion valve and flush system to heck and gone you may have the black death going on (compressor fluff from toasted compressor hides in condenser then you fix system it turns liquid and plugs expansion valve)

Full charge (assuming it is) compressor running and high side not hot and low pressure side not cold makes me think of expansion valve not expanding liquid into gas as is it's job in life.

It'd be VERY helpful to know what your pressures are high and low side with a/c on and compressor running but cools like heck sometimes and then nothing makes one suspicious of the expansion valve and if so why it has a problem.

 

Could be the metering block sticking open or could be the evaporator freezing over. Mine will do that sometimes and did it real bad when it was plugged with dirt and leaves.

 

I have had a gauge on the low side before . . it rar 40 - 50 psi while it was cooling well . . .
sometimes it does freeze up . . but it never even starts cooling now . .