Heater fan problem

[sibot]

Hi,

I noticed a burning smell and white smoke from the front heaters when trying to clear the windscreen this afternoon. I took the intake off and turned the fan by hand - quite stiff. I also noticed that the fan only moved itself when on Max. I've had a look here and found the FAQ which pointed to a corroded fan bearing, so i've stripped it down and it is indeed rusty (but not as bad as some pictures i found whilst searching). Is there anything in particular I should be using to clean the bearing, or will 3-in-1 suffice? And do i need to get it all back to 'shiny', or just the bearing and it's immediate surroundings?

Whilst everything was disassembled I also noticed the evaporator is in a bit of a state - how should I be cleaning this?

(It looks like the smoke was from the sponge on the hot/cold mixer flap which appears slightly charred in places, presumably due to being stuck full on hot without any airflow?)

Cheers,
Simon.

[g8dhe]

The lower bearing is probably best packed out with lithium grease rather than oil.
Clean up as much muck off of the armature and the copper commutator pads but take care not to damage the pads or wires of course!

[sibot]

Thanks. Armature and commutator pads didnt look too bad, was mostly the bearing, bearing cover and the brush holder that were rusted, but i'll give it all a buff up.

[Northern Bongolow]

do a search on here and type in fan AND resistor, and have a read, is your heater controls digital or manual , this is relavant as there are 2 different resisters. these get hot and desolder the lecky contacts inside, the search should show how to repair.
the foam needs replacing as it will let air in/out, best to keep fairly airtight.
the evaporator/heater unit should be really clean to allow max air through, best done with a tooth brush and an air line or foot pump.

[sibot]

Thanks, its got climate control. Found the fact sheet for replacing the transistor - fan only working on Max, but much better blow from it after cleaning the bearings and the evaporator. New transistor ordered.

I also managed to shear one of the captive bolts holding on the main heater body, and there is air escaping from where the sponge gasket is worn away. Is there a particular name for the kind of bolt i need to replace this, and where can i get one? Also what can i replace the gasket with - does it need to be anything special or will normal draught-excluder type stuff work?

[Northern Bongolow]

depending on how its snapped etc you could just drill down the remaining bit a little and screw in a good self tapper or similar of smaller thread than the original stud, or weld on a new stud or if its a bolt weld another on.
as it gets a tad hot i would go for a tube of suitable heat resistant sealer and make a flexy gasket, its not going to come off again is it.