The Climate Control modulates according to whether the cabin temperature is satisfied. Normally a change in temperature or distribution at the controller will cause the fan to run higher or lower. If this fluctuates illogically it may mean the in duct temperature sensor is faulty or a loose connection. Try setting your A/C say to 20C and then measure the temperature at the various outlets on the dash and at footwell level. The outlets never read exactly set set temperature but a near temperature.

 

you certainly can add refrigerate but where did it go? it leaked out thru a seal somewhere.
you don't add refrigerate to you house a/c or your refrigerator, do you.

 

If it wasn't doing this before you had it topped off by the mechanic, it is possible that he added too much. I've seen cars have too much Refridgerate and them cycle on and off like you stated it was doing. My first step would be to just get one of the little do-it-yourself kits from walmart and and check the level and add some if needed or let some out if needed. Its really simple. If you can air up a tire you can do this. Just make sure you connect the supplied connecter to the LOW side valve on the AC system. Should be a cap on it with a capital "L" on unless someone has lost it, usually light blue in color. The gauge is color coded so it's really easy to judge. When you disconnect the hose from the valve have some soapy water(or spit if you're gangsta) ready to put on it to make sure the valve seals good. You'll see bubbles if it didn't seal off good. Just mash the valve open and closed with a screwdriver til the bubbles stop. This may not fix it, but it would be my FIRST step. Partly because I already have said items. Everyone should have these items though.

 

A/C systems are simple heat pumps and the ability to transfer heat from one side of the vehicle to the other is essential for it to work properly.

These days its not for the untrained to do, simply because you can get it wrong and have a worse problem on your hands or reduce the life of the components which can get costly.

In any case venting refrigerant to the atmosphere is illegal and reckless behavior to state the least!

Consider this!
If the condenser cannot reject heat in front of the radiator because its all covered in grass hopper guts how do you expect it to allow the system to function as it should?
Equally if the condenser fan isn't working too well it will show very elevated high side pressures which will affect heat transference and the system efficiency goes down!

As "non qualified", a simply condenser clean with soap and water or even a coil cleaner might just restore the system to working efficiency. Basically the same can be said of the evaporator if it covered in fluff, dust, or a goop made up of stinking dog hair coating the matrix or worse rodents building nests in the box!

Next if you have a leak you need a leak detector to find leaks, without it you are just allowing refrigerant to escape to the atmosphere and add atmospheric pollutants unnecessarily.
I see a question-- Where do leaks come from? Well the obvious like hose connections/fittings and of course the charging points which are like tire valves and leak--just like tire valves do! Plus the gland seal on the compressor drive and leak as the compressor wears and loses pressure.

What might not be apparent is the fact that a PRECISE amount of refrigerant oil is suspended in the refrigerant to lubricate the compressor. Lack of refrigerant or too much will slow down the oil flow since it is dependent upon flow and lubrication starvation will occur.
Add too much oil and the compressor runs the risk of hydraulically wrecking the reed valves destroying compressor efficiency making the whole lot worse.

So you decide to go down to your friendly local parts store and buy a can of refrigerant. What size do you buy? I bet the sales guys who knows nothing about A/C will sell you a "big gulp" like at the McD's across the road!
Mores the better right--wrong!
Ask yourself what is in that can????
Refrigerant purity--who knows! Might be a mix of other gaseous junk !
How much oil in there? And is it compatible with what is in the system already?
If you put too much oil in the system it won't transfer heat properly and the system efficiency goes down! Plus you run the risk of wrecking the compressor!
AND Last--With sealant whoopdy do!--the A/C tech's nightmare!
Simply because eventually you might just throw your hands in the air and consult a mobile A/C shop to do it right!
Undeterred--- also there is personal risk!
Now without knowing what is in the system do you simply connect it up. If its been grossly overfilled (the cause of the problem) and the low side pressure is elevated, the can might just explode in your hand and the boiling refrigerant on your skin burn you causing blindness!

BUT we folk test the refrigerant for contamination including morons who mix Freon with R134a and other refrigerants in a vain attempt to make it all work. In short no shop will evacuate a system without a refrigerant analysis because it will cross contaminate the expensive recovery /charge machine in use. These pieces of machinery cost about $6500 a pop and sealant in them will cause about $500 minimum of repairs to fix it the expensive machine. Not to mention pump into another vehicle with a pure system!

If you have a problem and you want to DIY a compressor for example consult your local A/C shop to draw down the system the machine will check the refrigerant weight and purity which can be recycled--if you haven't filled it full of crap!

If you want to be taken seriously STOP calling it Freon--Freon is /was an Ozone destroying agent marketed by Dupont and referred to as R12 and subsequently banned under the Montreal Convention. It is a restricted product. Only people like me can buy it because I have an EPA license as an auto engineer to dispense refrigerants.
I hope this has been something of an info expose, however I haven't touched on HVAC controls, blend door operation, applied voltages to A/C clutches , fan drive and tensioners, belts to name just a few other very important parts that contribute to A/C efficiency.
T/V

 

Good write up TV.

 

My D1 does the same thing, but only when the fan is set on the 4th setting. I believe it is a faulty switch. Next time tap/hit on the dash at the blower setting switch, it should come back on.

 

This is massively helpful, thanks for sharing...

By the way, just to clarify, I don't prefer DIY if I don't know it well enough. For air conditioning, I always take it to a professional, though not someone who is a LR AC specialist. He is a general car AC chap.

Taking it to a LR dealership will simply not work out financially. These guys are crazy in their pricing!

Hence looking at all options before I go back to my mechanic- will potentially print these responses so that he can irradiate them one by one!

 

This could be the simplest answer- will surely check it. And yes- I too see this on 4th setting! Thanks for your response...