Can AC Compressor be always on?

[mike_nofx]

He all, i have recently bought a GQ patrol and the previous owner has had trouble with the AC switch or wiring and has just run a cable directly from the compressor to an aligator clip.
To turn on the AC you need to pop the bonnet and connect the aligator clip to the battery positive!!!

Anyway This means the Compressor clutch remains on when using AC, instead of cutting in and out (they normally cut in and out dont they?)
Will this damage anything?

Iam going to attempt to wire it up correctly, but if for some reason i cant, can the compressor be wired directly up to a switch (even the original switch if it works) with ignition power and the relevant fuses etc?? This would mean clutch is constantly engaged when AC is on.

Thanks

[date]

Simple answer - No! If the A/c compressor runs all the time, the gas will be pumped through the condenser all the time, causing very low temperatures in the incoming cabin airflow. The moisture in the incoming air will freeze and there will be no air coming into the cabin. I had an A/c compressor clutch problem years ago, and we had small flakes of snow coming into the cabin - when the thing hadn't completely choked off the airflow.

[PBBIZ2]

Date,
I have had this happen in NT when the aircon in the room is left on 24/7, but the room is a lot more sealed up than a vehicle, which has lots of air leaks and venting, plus the constant heat load from the engine and the environment. I would have thought it wouldn't matter too much unless the inside of the vehicle gets really really cold, maybe the sorts of alpine temps you get in winter?
The aircon in the room was spitting out snow and ice and then stopped completely as it was totally iced up on the coile inside the room.
Anyway, first I have heard of it in a car, maybe about to learn something new!

[date]

PBIZ2: I can assure you that once the airflow slows it ices up very quickly. This is the reason that you have to have the fan running whenever the A/C is on. I had this happen in Autumn and it wasn't particularly cold that day. Once it has iced up there is little you can do other than wait for it to tahw, and this will not happen if the gas is still circulating.

[PBBIZ2]

Yep, didn't pick up that the fan would not be running also. Agree with the comments you made.

[ozy1]

just so you know, if you do run it this way even for a short term make sure your fan is running, if you dont run the fan for some reason, you will freeze the evaporator,

once the ice forms, it can actually crush the evaporator tubes, which can cause cracks and leading to leaks, then you will be up for a cost of a new evaporator not fun changing them

[Struddy]

No, the wiring for the magnetic clutch is wired to the A/C cab switch which will only come on when the fan is on. But

The major problem is that the clutch will also not come on until the Low Pressure and High Pressure switches are closed which are also inline on the same circuit.

Bypassing these switches could result in the high side of the system pressures getting too high and will likely end up blowing a rubber hose out of its crimp fitting. Which will make the Greenies unhappy as you have just killed 10 penguins and you will be unhappy because you now not only have a wiring problem but need a new hose and a regas.

If you a still running with the aligator clip remove it now and run with the windows down until you can fix it or afford to get it fixed or it will end up costing you more.

Struddy

[brianjames1984]

I suggest starting at the thermostat which is located near the evaporater behine the glove box which might be the main problem which will allow the compressor to cut in and out.

If the a/c comp is wired straight to the battery it will run non stop even if the fan is off that comp will still be running because the compressor has been wired direct to power and after a while of it running the pipes will freeze up and cause the compressor to sieze up and causeing a whole heap of damage.