VN Aircon problems

[madmike]

Hi there I'm having problems with my Air con.It works when its a warm day but when it's a hot day it works for a while then the compressor pump stops working.Has anyone have an idea what this may be??

[VQXTC]

Hi Madmike,

I would get the aircon gas level checked by an automotive airconditioning specialist. At least that way you can rule out anything to do with the aircon gas.

Hope this helps,

Cheers

Simon

[hi_ryder]

might need a recharge. unscrew the cap on the unit near the fire wall and press it in with a pen see if any gas comes out. the compressor cutting out usually means your gas has leaked out. in most cases its the 2 little O rings where your ac lines bolt to the compressor. if you do get it re-gassed get these swapped out with new ones. also are you running a trans cooler at the front? if so, make sure its not directly against the condenser. otherwise your system will struggle to keep cool, and youll cook the O rings letting your gas leak out again.

[Warranty Void]

The compressor will cut out if the system overheats. Reasons for this include your condenser being full of crap in between the vanes (the skinny silver radiator thing in front of the engine radiator), the engine radiator being full of crap between the vane things, your condenser fan not working or your radiator fan not working.
A good place to start is to use a pressure washer and clean out the radiator and condenser vanes carefully.
I think you will be pretty surprised at how much crap can be in there.
Just to be extra careful I am talking about cleaning the outside of the radiator and condenser.
The engine radiator affects the air con because the air that cools the condenser will have nowhere to go if the rad is not clear.
The fact that the air con works for a while pretty much means you have gas in the system. The other place to check is the reciever/drier which is the silver thing that looks like a beer can under the bonnet. If the air con is working this bit gets really cold.
Don't let the gas out to see if there is any gas. You may as well let it all out and then you can say yep I'm sure theres no gas now.
Once the radiator and condenser are clean check the fans by idling with air con on and watching for them to start.

[madmike]

Sorry lads I 4got to mention that I just had the Aircon regased and the termo fan in front of the condenser is always on when the aircon is switched on. Overheating to me sounds like the problem cuz it only happen's when it is really hot.There was a trans oil cooler at the base of the bumper bar but I relocated it up behind the grill. I'll clean out all the muck from in and around the condenser and radiator and see if any thing comes of it. Cheers Lads for your help.

[hi_ryder]

make sure theres a good gap between the condenser and trans cooler, never mount them directly against each other.

[baalamb20]

hey, the same thing happened to me too, a mechanic told me it's probably the compresser that's gone, so he quoted $500-600 for a new compressor and $200 for a regass, I took it to a a/c specialist and it was a Low pressure switch on it's way out, cost me $90 fitted, good as new

[madmike]

The Low pressure switch hey baalamb20,see if this sounds like your problem.Ok it has happened again today .I turn on the Aircon and all is good then it just stops blowing cold air so I left the Aircon running opened to bonnet to check it out.The fan is running but the compressor pump is not.SO ok then I checked the relay replaced it and still nothing ????It's really piss'n me off.

[mischa]

There are 3 reasons in a non climate controlled c ar that the compressor will turn off. Low pressure switch, high pressure switch and the ac & fan switch.

Take out to a ac tech who will test the pressure is right and the purssure switches are not faulty. Even if you could diagnose it your self changing any pressure switch will cause the gas to escape.

Ps, leave the font settings alone.

[madmike]

I replaced the high pressure switch only because i know that it has a valve in there to stop the gas coming out and it made no difference so I bypassed the low pressure switch, dont know if there is a valve in the receiver/dyer and it works ok.Faulty low pressure switch i think.

[mr031]

the clutch coil might be going open ciruit, you need a voltmeter on the power wire to the compressor, if you have 12v when its not working, the clutch is not clicking in! Sometimes its just a matter of removing a washer between the clutch plates.

[Jxw]

certainly should be a valve in there, just be quick when removing/installing it to reduce the amount gas escaping, won't hurt to replace the o-ring also when you're at it if it doesn't look to 100%

[baalamb20]

hey madmike, yep that sounds like mine spot on except, this happened to me a couple of years ago and silly me believed the stupid mechanic that the compressor died, so I had to put up with 40 degree temperatures driving around lol for 2 summers. then only a few months ago I thought i would turn it on for kicks, cause usually you can hear the clutch engage instead of just the thermo fan at the front and it came on, I thought wow i have ac again and about 2 minutes later it went off again and I thought hang on, if the compressor has died and there is no gas in the system how come it came on, so i went to an auto specialist and he did a few tests and it was the low pressure switch, I thought it was too cause i sprayed wd40 on the electrical plug and the ac worked for a while. He said apparently it's common for the low pressure switches to go on the VN's

[madmike]

Thanx heaps for that baalamb20. the compressor does work so I didn't think that was the problem.time to get a new low pressure switch and fingers crossed that fixes the problem.Thanx everyone for your help.Cheers

[bcw61]

hey madmike, yep that sounds like mine spot on except, this happened to me a couple of years ago and silly me believed the stupid mechanic that the compressor died, so I had to put up with 40 degree temperatures driving around lol for 2 summers. then only a few months ago I thought i would turn it on for kicks, cause usually you can hear the clutch engage instead of just the thermo fan at the front and it came on, I thought wow i have ac again and about 2 minutes later it went off again and I thought hang on, if the compressor has died and there is no gas in the system how come it came on, so i went to an auto specialist and he did a few tests and it was the low pressure switch, I thought it was too cause i sprayed wd40 on the electrical plug and the ac worked for a while. He said apparently it's common for the low pressure switches to go on the VN's

I also had a failure of the low pressure switch on my old VN. The aircon would work initially for a few moments, then the compressor would disengage. I simply disconnected the connector from the switch and fitted a jumper wire across the plug terminals, and the system worked fine for a few years up to when I got rid of the car.

I did buy a new low pressure switch, but never got around to having the system gas discharged and replenished in order to change it.

[Jxw]

I also had a failure of the low pressure switch on my old VN. The aircon would work initially for a few moments, then the compressor would disengage. I simply disconnected the connector from the switch and fitted a jumper wire across the plug terminals, and the system worked fine for a few years up to when I got rid of the car.

I did buy a new low pressure switch, but never got around to having the system gas discharged and replenished in order to change it.

my vn does this when i plugged a gauge into the lp side to check how much gas was in there, gas was showing a bit low and the extra release in pressure with the hose and gauge on the system it would turn on, spin for a bit, pressure would drop, switch off pressure would rise when off then back to the start of the cycle switching on and off, with the gauge and hose disconnected it went back to working normally... i guess i should recharge it one day but it's working ok atm....

[madmike]

I just had my car Idling in my driveway with the aircon on and it works fine but as soon as I bring up the rev's the compressor pump would disengage on not come back on for what seemed to be eternity . I had a spare low pressure switch that I tried and it seemed to work a bit beta but still the same end result.GGGRRRRRR.

[Warranty Void]

Get a quote from an aircon place and at least you might get a diagnosis for free.