AC cutting in but not out?

[losh1971]

Anyone know why my AC cuts in but runs for at least four mins and still won't disengage? I thought it was supposed to cut in and out every three or so mins?

 

[vs-lover]

Losh,

It'll stay on for as long as it takes to get the area cool via the thermostat or otherwise it will cut out when the high pressure switch is tripped so as to avoid the system icing up.

 

[losh1971]

Losh,

It'll stay on for as long as it takes to get the area cool via the thermostat or otherwise it will cut out when the high pressure switch is tripped so as to avoid the system icing up.

Could low gas do this? It doesn't seem as cold as it was six months ago. I felt the pipe in the bay and while it was cold it wasn't iced like I think it should be.

 

[Trevor loves holden.]

If it turns off within 4min then your low on refrigerant, the compressor has to build up to around 16 bar then it gets pushed thru the condenser turning the gas into liquid as it cools then travels through the drier to remove any left over gas as you don't want gas going up to your tx valve, that 16bar then lowers to around 3 bars as liquid squeezes through the little hole and the liquid starts to boil going through your evaporator where your fan blows air through cooling the warm air down, then the liquid goes back to the compressor and starts over. something like that.

So until the pressure is reached it will keep running, so until the temp in the car has cooled down enough then you will see the compressor kick on and off to stop icing up the evap. If it was low on refrigerant then it will stop and start rapidly as it needs to wait for the liquid to return to pump before it can start.

 

[mechanic]

then travels through the drier to remove any left over gas

water. The drier removes water and other contaminants in the system. A drier contains the same silica desiccant beads that you get when you buy a new pair of shoes.

 

[Trevor loves holden.]

water. The drier removes water and other contaminants in the system. A drier contains the same silica desiccant beads that you get when you buy a new pair of shoes.

Yes moisture.