Noise from Air con fan

Defender 90 1997 300TDI

I have a noise coming from my air con fan, sound like there is a budgie stuck in there , noise stops if I turn air con off.

my question are the bearings sealed on the fan motor or will a quick spray of WD40 fix it.

if you can get to it a dose of three in one oil wouid be better on plain bearings

I think I should have mention it's the fan inside the cab, passenger side foot well.

Is it a major job to get to the motor?

Normally the outer bearings on motors get dry if you can see the fan and shaft then light oil is far better than wd as wd40 evaporates

Could I use silcon oil?

Sounds like the right diagnosis as here in South Africa we encounter lots of dust.

most fan blowers I have sorted on other make use nothing more than plain phosphor bronze bearings.
in motors these were impregnated over night in light oil eg 10w40 will do/ wiped off and fitted.

I would see if you can drip a small amount of clean engine oil on both bearings. gently spinning it by hand with a couple of drops of oil on motor shaft either end-should get capillary action into bearing

ok will give it ago after work tomorrow, and will report back, thanks for your help