Diagnosing AirCon - where to begin.

[clivvy]

hi chaps,

I want to start diagnosing my air con (not working) but not sure where to begin. ON my Fiat Stilo it was the easiest thing to do - I just hooked up my laptop and it told me it was the sensor.

Does the Nissan Software do this, I cant remember?? My consult is for a 14pin ODB, I can see adapters that fit the 16pin I have in this Terrano, but I wonder if the cables from my Stilo reader will work?

:bow

 

[solarman216]

First thing to do is locate the two fill points on the pipes, remove one of the plastic covers and with a small tool press the pin in a little, gas should hiss out at a fair pressure, similar to a car tyre valve, if no gas then it will not run as it has a pressure switch that disables it, Rick

 

[clivvy]

First thing to do is locate the two fill points on the pipes, remove one of the plastic covers and with a small tool press the pin in a little, gas should hiss out at a fair pressure, similar to a car tyre valve, if no gas then it will not run as it has a pressure switch that disables it, Rick

fair point, I haven't done that yet and I suppose with no gas, I wont know what has failed if anything!

ok, ill go blip the valves and see what happens!

 

[rustic]

fair point, I haven't done that yet and I suppose with no gas, I wont know what has failed if anything!

ok, ill go blip the valves and see what happens!

Wear gloves... expanding gas can freeze things that are close by...

 

[clivvy]

ok, blipped the first one, tiny hiss then nowt. Blipped second one, tiny hiss then nothing, so its empty that for sure!

well, ill go get it tested next week at Kwik Fit

 

[solarman216]

you will probably find once they have charged it, it will work OK but you have a leak (unless a pipe or two were disconnected for other work) and unless you can find it, it will empty itself again, you are better off if it leaks out in a few days as you will stand a better chance of finding it, if it takes a couple of months then such a slow leak will be very hard to find, Rick

 

[Lazy-Ferret]

Before you go to quickfit, check to see if they use the gas with the ultraviolet dye in, if not go to HalFruads, as they do (But double check, just in case it is different over your way).

Then when they fill it up, if it should have a leak, it's just a case of shining an ultraviolet light around the aircon components, and you can see where the leak is.

Halfruards also sell a aircon rubber "O" ring set for a couple of quid, which has green rings in a variety of sizes, so if it is just the old rings have hardened in the joins, it is a very easy job to replace them. Apparently, something in the newer Aircon gas attacks normal black "O" rings, but they did not know this in the early days, so some systems were still being fitted with the black rings, but having the new gas inserted. The weird bit is, they would mostly be OK, until the system dried out, then they would break down properly, and start leaking when it was re-filled.

 

[clivvy]

great advice mate, thankyou, I will do just that. I have no idea right now if the dryer or the compressor are working, which is a shame because it will cost money to find out!

I wish I could just get a cheap can of gas, just so I could add a little to see if the system turns on or not!

Before you go to quickfit, check to see if they use the gas with the ultraviolet dye in, if not go to HalFruads, as they do (But double check, just in case it is different over your way).

Then when they fill it up, if it should have a leak, it's just a case of shining an ultraviolet light around the aircon components, and you can see where the leak is.

Halfruards also sell a aircon rubber "O" ring set for a couple of quid, which has green rings in a variety of sizes, so if it is just the old rings have hardened in the joins, it is a very easy job to replace them. Apparently, something in the newer Aircon gas attacks normal black "O" rings, but they did not know this in the early days, so some systems were still being fitted with the black rings, but having the new gas inserted. The weird bit is, they would mostly be OK, until the system dried out, then they would break down properly, and start leaking when it was re-filled.

 

[briggie]

briggies tips .....diagnosing air con faults

to diagnose a air con fault .....

switch it on ...... does it work ..no ? ..... its broken then

 

[clivvy]

that's a great help Briggie, truly you are a diagnostics genius.




:thumbs

 

[jims-terrano]

Have you tried removing the clamp on the front panel to allow you to examine the pipe at that point as that is a common place to wear through.

 

[clivvy]

Have you tried removing the clamp on the front panel to allow you to examine the pipe at that point as that is a common place to wear through.

not yet Jim, that's tomorrows job though I have examined what I can see and apart from much on the dryer everything is clean and seems corrosion free - I've just that clamp to check. Tomorrow i also want to check that the clutch is working, anyone know how I go about it?

 

[solarman216]

not yet Jim, that's tomorrows job though I have examined what I can see and apart from much on the dryer everything is clean and seems corrosion free - I've just that clamp to check. Tomorrow i also want to check that the clutch is working, anyone know how I go about it?

If you are talking about the AC clutch, the just above the AC compressor is a connector on the single wire that comes from it, apply 12 v+ with the engine running and the pump should run, do not run it for more than a few seconds with no gas, you can also do it from the switch on the filter/dryer but I cannot remember which wires to short as I think there are three, if however you are talking about the engine clutch, then start engine, foot on clutch, engage gear, foot off clutch, engine stalls, all working properly, Rick

 

[clivvy]

If you are talking about the AC clutch, the just above the AC compressor is a connector on the single wire that comes from it, apply 12 v+ with the engine running and the pump should run, do not run it for more than a few seconds with no gas, you can also do it from the switch on the filter/dryer but I cannot remember which wires to short as I think there are three, if however you are talking about the engine clutch, then start engine, foot on clutch, engage gear, foot off clutch, engine stalls, all working properly, Rick

yes, talking about compressor Rick, I will try what you suggest, at least then I can eliminate one possibility before spending money on regas. :thumbs

 

[solarman216]

yes, talking about compressor Rick, I will try what you suggest, at least then I can eliminate one possibility before spending money on regas. :thumbs

They rarely fail and if they do it is cos they lock up and run all the time which blows the compressor, Rick

 

[clivvy]

They rarely fail and if they do it is cos they lock up and run all the time which blows the compressor, Rick

cheers Rick, going to test it today. I do hope its ok because I can handle changing the pipes on an empty system, but don't fancy changing the compressor or the cost!

Not sure how to test the dryer, but apart from needing a clean it looks intact...!

 

[AlexD333]

to diagnose a air con fault .....

switch it on ...... does it work ..no ? ..... its broken then

:jesterbg