Morris Minor Owners Club

Hi

My '62 MM has a early round type heater with a rheostat on the front. The fan or motor recently started screeching, this stopped after a squirt of WD40 the slots in the heater's front facia. It then started doing it again followed by a loud clattering sound.

I have removed the entire heater. Judging by the state of the foam and the dust inside it hasn't been opened up before.

I connected the fan motor (still fixed inside the matrix, but with the plastic front unclipped and away from the fan) to a battery and it ran perfectly with the two speed rheostat operating fine. No screeching or clattering noises.

The fan doesn't appear to be loose. Does anyone have any ideas of what may have happened?

Fitting the heater unit back will probably be a bit of fiddly job, so I'd like to make sure it doesn't just do the same once it's in.

Mine did this and the fan was hitting a loose wire . After a good clean all was well.

Screetching - dry/worn bearings in motor. Can be intermittent - and often worse when first turning on the fan when cold. It is possible to remove the motor and you may be able to see some way of lubricating the spindle. As above, clean what you can.
Clattering - fan hitting something. Make sure when you put it all back together it still runs as it should before replacing in car.

Any signs of metal on metal contact?
Screeching is a sign of not just of worn bearings themselves, but of possible worn bearings, or other wear issues, allowing the actually moving parts to rub inside the casing.
Clattering, as myoldjalopy says, is an out of balance issue.
I don't know what the internals are to the fan you've got, is it a cylindrical arrangement?

It's a round heater with round matrix and fan through the centre. Rheostat is mounted on the front plastic/bakelite facia.

Thanks for your replies..

I'd be checking for any shiny polished marks on the inside no matter how small.
That'd explain why the squirt of WD 40 cleared it up for a while.