Defender blower unit

[dmdigital]

Blew the fuse on the blower unit fan so replaced it and blew that too, so before I put another one in...

It's too damed wet at present to work on anything (and there's a possibility of a cyclone forming) so I thought I'd ask the question:

Is there anything that usually causes this in Defender?

I've had a fair amount of rain water through the front vents... I must remember to close them, but I'm still forgetting to. So I'm suspecting the switch maybe.

[vnx205]

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.

[dmdigital]

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.

[vnx205]

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.

[dmdigital]

Well I had a look this afternoon and drained about a litre of water out of the air intake to the fan. So if its fine this weekend I think I'll be checking the fan unit out.

Looks like I need to block the air intake with one of those ram/scoop style vents or improve the drainage.