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| GregK Myanmar Member Since: 18 May 2016 Location: Yangon Myanmar Posts: 22  
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Ok here is a question that comes up when you take out the whole dash there is a controller there that does not appear in the parts manual anywhere. It is some kind of temperature sensor with a wire into the main ducts of the air con heater system.
Does anyone know what it does as my mechanics disconnected it from the harness a while back and told me it was not needed but I have my doubts.  Click image to enlarge Click image to enlarge Click image to enlarge 2010 Defender 110 Puma 2.4 TDCI. |
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15th Feb 2017 5:53pm |
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| davidpalfreyman Member Since: 06 Oct 2010 Location: tanzania Posts: 67 
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Greg,
There was certainly nothing like that when I removed my dash. Don't know what it is. Sorry. Any progress with finding an evaporator? David |
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21st Feb 2017 1:21pm |
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| GregK Myanmar Member Since: 18 May 2016 Location: Yangon Myanmar Posts: 22
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Yes lots of progress. Lucky me. I found a Chinese made one here at a friends workshop who also owns a Defender Puma. Was a little bit more than I wanted to pay $300 but it was time saving so I bought it and fitted it and its working better than I ever remember it working. The compressor is turning on and off properly the core is cooling and not icing up. I have left the heater core out so I can watch it for a while. I have learnt a lot and put back a lot of stuff to go on a 2000 km drive without the front dash. But I am pretty happy to have fixed it after all these years of it leaking and not really working.
Really it appears that all the dust and fluff that gets in there because there is no micro or pollen filter on this system is also an issue. There is a lot of poor design in this system. Lets see if it works for a few years. Its worth considering cleaning this every few years. I have lots of photos and some videos which I am still working on in a word file write up. The photos came in handy to see where the wires, cables etc go when its time to put it back together. I have also learnt that the Landrover wiring diagrams are quite useless too. Hard to work out even the colours as there is no key in the manual. That extra part on mine was in line on a wire that has something to do with the turning on the fan when the AC button is turned on but fan slider is still at position 0. It used to pulse when that was inline on that wire. I believe that it is set at a certain variable temp to open and close and gives that pulse effect. It used to go on for minute and then go off for a minute when fan slider was set at 0. Now it just stays on. 2010 Defender 110 Puma 2.4 TDCI. |
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21st Feb 2017 3:32pm |
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| dorsetsmith Member Since: 30 Oct 2011 Location: South West Posts: 4554 |
2.4 defender wiring KEY
Click image to enlarge |
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21st Feb 2017 4:32pm |
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| GregK Myanmar Member Since: 18 May 2016 Location: Yangon Myanmar Posts: 22
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That key will help in future. Thanks. Dorsetsmith.
Here are two new videos I made that might give some help to others. Part 1. Part 2. 2010 Defender 110 Puma 2.4 TDCI. |
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21st Feb 2017 5:22pm |
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| WhiskyJackR Member Since: 25 Nov 2014 Location: Lizard Posts: 159 
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Useful video's Gregg. Thanks for sharing. Any farther South and I'll need to trade the Defender in for a Landing Craft
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23rd Feb 2017 12:33pm |
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| GregK Myanmar Member Since: 18 May 2016 Location: Yangon Myanmar Posts: 22
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Ok so that controller that I mentioned a few posts back is an important piece of the control system of the air con system.
Even though I cant find it in the workshop manual or the parts manual and it is original equipment. After my long trip I realised I could test it with a voltmeter set on to continuity. Basically it is a thermostat sensor of the output duct and when the air gets to a certain amount of cold it makes a click and opens the circuit and disconnects the compressor. It is placed as a break in the wiring going from the AC push button on the dash. Mine is a 2010 model. When the air warms up again it clicks and turns on the compressor again. So it is a preset in factory thermostat. With it in place and fan set to 0. and the aircon turned on it will act as a pulse switch. The aircon and fan will go on till it gets cold and then it will turn off the fan as well as the compressor. When it heats up again it will click and turn on again for another burst. If the fan is set on 1,2 or 3 then the fan will not disconnect but the compressor is being controlled by that thermostat and is being turned off and on by it but the fan will continue. You may not notice then that it is doing its job. The thermostat can be preset as a variable unit and is left at that setting. At maximum clockwise position the thermostat will operate at the coldest and at anticlockwise as the least cold. This is one method in itself that would stop the evaporator from icing up independent of the other controller in the evaporator which does not seem to work as well. Go figure...... Also I have done a little research and realised that it is absolutely essential to replace the receiver dryer at the time the evaporator is replaced. Ordering that part now. If you dont do that any residue moisture that has gotten in the system will turn to ice inside the system. The R134A coolant cannot freeze inside at ordinary temps as it has a boiling point of -26.1°C. Yes that is minus 26.1°C. Ok so therefore any moisture inside an air con system is an issue and any time it has been opened to the atmosphere and during the time the evaporator has been leaking it will be letting the atmospheric moisture in. So also the reason the evaporator ruptures in the first place is probably the ice build up on the outside of the evaporator which cracks it. If too much ice builds on the evaporator the air cant pass through and efficiency of cooling is lost. The evaporator is blocked by the ice. So these controllers and the thermostat are there to keep the system in the efficient range of cooling but prevent icing of the evaporator. Thats the update for the moment. More to come as I still have the dash out. Seems quite normal now. 2010 Defender 110 Puma 2.4 TDCI. |
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1st Mar 2017 8:29am |
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