So it's friday which means I can pretend to be doing something on the Defender so the wife doesn't think I bought a heap but infact I am trying to figure out how to fix theHeater Blower.... If indeed it needs fixing.

Again, I am brand new to Land Rovers, last car I had you turned a dial, heat came on, turned another, said heat went cold.

Defender, I have 3 levers - 2 on the right, one on the left. I am sure mine is nothing special and yours also have said levers.. HOWEVER! - Mine don't do much.

The two on the right, they move up in unison, one of the handles is bent and touches the other, i presume that this shouldn't happen. Although moving them up, or down - doesn't make any air come into the cab.
I presume the one on the left, with the label 0 to 2 should make the air come into the cab. - It doesn't. It makes a bang sort of noise in the engine bay, but no air.

SO my question is, how do I fix it? I have looked around a little, some say motor might be blocked or look here or look there but I am utterly clueless with this. Should I just buy new ( used, but new to me) unit? or is there an easy fix? - I presume that because the left lever is making a bang that it is operating something. And I can see the right levers moving cables that move something on-top of the heater system?

The lever on the left 0-2, is the fan motor speed. In other words, as you turn this up to 2 the harder the air blows through. If it causes a 'bang' sort of noise then maybe it's jamming? The air intake duct-work to the fan has a 'birdsmouth' valve on the bottom of the duct pipe. This can clog with muck, the duct fill with water and flood the fan motor. This can cause corrosion in the motor. Do you suffer from condensation on the windscreen?
On the right, one control lever adjusts the temperature with a cable going to the heater box. The other lever directs the flow up to the windscreen or down to the footwells, via a cable through the dash to a flap above the passenger footwell. Those two levers should not be touching and do not work together. There are a few screws on the right hand side of the dash, which give you access to those levers.

The condensation hasn't been too bad - had one morning when I needed to give it a wipe but the weather was all over the place then.
Should I be able to hear the motor when I turn the key but before I turn the engine over?

Avoid changing the interior light bulbs for LED units, the heat given out by the bulbs is the best source of heat in the fender.....

Waiting to be shot down...

How old is the Defender?

You should be able to hear the fan with the engine off; indeed this is exactly what it was designed to do in the earlier years. It was one of the most successful whirring noises of its generation. It was only the failure to explain this properly in the manual that in later years led LR to follow the herd and attempt to use the fan to actually blow air into the cabin. Not many people know this, but the real reason for axing the Defender production was that they had reached a stage where the entire engine output was being used by the alternator trying to drive the fan hard enough to demist the top of the windscreen. An admirable goal, but even die hard buyers were never going to put up with 100% immobility, even if that wasn't much worse than what they already had.

Wife (on getting her 300tdi CSW) "There's a bit of a draught coming into the cab when l am driving along"
Me "ls it warm or cold"
Wife "Slightly warm"
Me "Oh, that will be the heater"

To be fair to the comedic comments above, don't expect great things from the heater. However, yours does not seem to be working properly. Even for a LR Defender!
Yes, with the ignition on you should be able to hear the fan. I mention condensation on the screen because if you have water lying in the air duct it comes through the duct work and condenses on the screen. As you are thinking, a good starting point is to see if the fan is actually working.
To repeat boguing's question. How old is it?

The defender is 21, she's a 1995 model. I'll get in the engine bay tomorrow and have a mooch around.

push the left hand side slide all the way to the bottom amd the right hand side ones to the top, if the fan is heard to be working but bugger all is coming out of the vents the flap that opens to allow the fan to blow in is stuck. If so look for the cable and flap on the left hand side of the heater box and either disconnect it and push it down or just try and push it with the cable connected.
You should then get air onto the windscreen

The left control performs two functions, the Bowden cable operates a flap to let air flow through the system, knob up / flaps closed , knob down flaps open . It also controls the fan speed, fully up = fan off, first position (about an inch from fully down) is low, fully down is high speed.

Had a fan that had stopped workinglast week.
Took the cover off of the wing and reached in, found the fan had jammed, gave it a blast of wd40 and a few twists by hand and then tried it again. hey presto, a noisy fan.


Cheers

If yours is anything like mine there are some bits of corrugated tube inside the dashboard directing the air to the dash top vents. These can easily be displaced, by vibration or by people taking the dash apart trying to make the instruments or wipers work. So they're worth looking at too. The cables from the levers to the heater box seem to be prone to breaking or coming off the heater box controls completely.