Thread: Defender blower unit

Don't know whether the Td5 heater fan is the same as the 300 Tdi, but I had the same problem.
I found that the little bleed valve at the bottom of the air intake for the heater was full of mud which had completely blocked the valve. It is a smaller version of the one on the air cleaner. As a result, the fan unit was about half full of water and the fan motor was submerged. I don't know how ling it had been like that because I had just bought the vehicle second hand.
Because I had removed the windscreen washer reservoir and the air intake, I was able to turn the fan by hand. It was pretty hard to turn.
Removing the heater unit looked like a bigger job than I had time to do at the time, so I tried another solution. Anyway I was about to head to the NT in October, so I didn't expect to need the heater fan.
Even though I assumed the fan motor would be sealed, I undid the small plate at the back of the fan unit and squirted in about half a can of RP7.
I spent a lot of time spinning the fan by hand to try to free things up. Eventually the fan seemed to turn a bit more easily, so I fitted a new fuse and tried again. The fan motor was obviously working pretty hard, but it didn't blow the fuse.
I didn't use the fan for a few months, but I repeated the treatment and the fan seems just about normal now and has not blown a fuse.
This is just a long winded way of saying take the air intake off and check that the fan motor turns.

Thanks, mines a 300Tdi (98) too.

Given the amount of rain in the last few weeks I wouldn't be surprised if this is the same problem. So if it stops raining I'll have a look at it.

It may sound strange but having the heater blower work in the wet season up here in the NT is the quickest way to demist the windscreen.

Just read your post more carefully.
It seems it is your 99 300 Tdi that is having the problem, so should be the same setup as my 98 300 Tdi.