Heater fan keeps blowing the fuse!

Well, just been out working on this...

So what I've done:

First I unplugged the heater box from the rest of the wiring, put a new fuse in, turned the fan lever down all through the clicks and nothing happened, obvious as the heater wasnt plugged in, but the fuse didnt blow either..... meaning it's not shorting on the wiring or the lever switch..... correct MHM? (you are the electrictry man) lol

Then I took the air intake out (what a fokin pain) to find out loads of frozen water in the heater....



couldnt get a drill bit in there, so got the dremel out with a small disc cutter and cut a slot at the bottom while the hair drier (2nd one) melted all the water, there's nothing in there now.




so, then I connected the heater box plug back on, already had a new fuse in the cab, turned the lever down, nothing on 1st and 2nd click, 3rd click the fuse blew.... meaning its shorting on the heater, isnt that right?

what next?
get the heater box out?
even if I do, i dont really know how am i going to test or check where its shorting....

what are your views?

YUp - yu have tested wiring is all OK.
As I said before, i reckon the fan motor is siezed (shorted to ground) and posns 1 & 2 thru resistors limit the current. Posn 3 is direct to ground, hence "POP".
yu need to take the fan assembly (heater box?) out and check it out externally.

I just had my heater box off..there is no wiring at all apart from the pack you have already tested...i cant see the point of taking the box off..its also an arse of a job if you haven't got help...bolts in the footwell, head in the engine bay..octopus time..

My guess would be the lower wiring pack bit thats coming from the black box itself has a split wire/bad earth/bad connection.

pedantic bugger .
yes - i meant the bit shopwn above that has the wires going to the fan - coz its the only bit left. It cant be split wire or bad earth or bad connection, coz none of them would not blow a fuse. It has to be something that is causing a low resistance/short between the power wire and earth.

just wondering if the motor aint just burnt out as the fan was solid in ice ,
as storm says its a 2 man job to get it out and back and a bitch of a job at that.

storm, the wiring I've tested is just the wiring that goes into the cab, the wires coming out the heater box (shown in buster bus pic below), its the bit that I've not tested and likely to where the problem is...



but to test these wires I think I have to take the heater box out...?

looking at it, seems like there's loads of space to take it out, is it just the bolts that make it a headache to get it out because of being nuts in the engine bay and bolts in the passenger footwell?
because if that's the problem i can get around it by using mole grips to hold the nuts in place?

buckshot said:

just wondering if the motor aint just burnt out as the fan was solid in ice ,
as storm says its a 2 man job to get it out and back and a bitch of a job at that.

Click to expand...

2 man job..!!
how many sugars in your tea mate? the bacon is on the frying pan..

buckshot said:

just wondering if the motor aint just burnt out as the fan was solid in ice ,
as storm says its a 2 man job to get it out and back and a bitch of a job at that.

Click to expand...

I hear wot yu are saying - but either way - it aint working - he has to take it out to be able to rectify the fault - or just go with no heater. will still need to remobve it to fix.

[JP];1281674 said:

storm, the wiring I've tested is just the wiring that goes into the cab, the wires coming out the heater box (shown in buster bus pic below), its the bit that I've not tested and likely to where the problem is...

but to test these wires I think I have to take the heater box out...?

looking at it, seems like there's loads of space to take it out, is it just the bolts that make it a headache to get it out because of being nuts in the engine bay and bolts in the passenger footwell?
because if that's the problem i can get around it by using mole grips to hold the nuts in place?

Click to expand...

cant you not run a curcuit test on those wires ?

[JP];1281676 said:

2 man job..!!
how many sugars in your tea mate? the bacon is on the frying pan..

Click to expand...

really mate you would not be happy if i turned up today got this bitch of a cold (not man flu been out for 2 hours with the dog this morning)

buckshot said:

cant you not run a curcuit test on those wires ?

Click to expand...

wot will that achieve? it will only show a low resistance or short to ground - he already knows its in that bit. The next thing is to remove it and rectify.

remove i think will be the easy part for me... rectify.. well, that's a whole different story! lol

I need to go to the post office now, so as its proven the problem is not on the wiring inside, im going to put the clocks back together and drive there whilst freezing my tits off...lol

JP...as youve tested the others without a prob i'd say yes...if you can get to them..it is a bitch..maybe take that plate off to get into it..

If it makes you feel better..i managed to get the box off in 5 mins with a mate...then i got flu and the snow came and minus 15 degrees..i have a 40 mile trip to work so, against better judgement, left the 90 at a garage..

He charged me 6 hours labour to replace the matrix and put the box back on, glad i supplied the parts....FTW!!!

once yu taken it out, JP - yu can bring it over here and we can check it out further, if yu want?

MHM, that would be brilliant mate!!

I just got back from post office, took the C5 instead as the main roads are clear.... altough the damn thing almost didnt make up the hill into my estate!

I'm going to give it a go at taking the box out now, will update shortly

10min job...
could have been quicker if I had ratchet spanners to take the bolts on the bulkhead

to actually get it out I had to cut 1cm of the metal bracket that holds the inner arch to the wing, but was just a cut to be able to bend it back as the blower was hiting on that...



MHM, can you PM me your postcode as I cant remember exactly your street?
can I go in a bit?

Wait til you try to put it on again...hehe..

well.. i hope you are wrong lol!
was pretty easy to get it out, wasnt forced between any parts or anything, and ive noted the angle it came out...so it just needs to get back in the same way.... i hope!

sell the defender and buy a rr..i have to turn my heater down i get that hot..

Looks like you've got same set-up as me..disco 200 in a fender with the original air filter...just watch your pipework and be aware and old matrix doesn't like being shaken about...be an arse to put it back together and find the matrix has sprung a leak.