Technical Heater fan - control issue

[BooBooDevere]

So the heater fan works from speeds: 1 - 3, but cuts out on setting: 4.

Any idea what could cause this?

Thanks.

 

[bugsymike]

So the heater fan works from speeds: 1 - 3, but cuts out on setting: 4.

Any idea what could cause this?

Thanks.

I am guessing a faulty resister winding where the tapping/ wire comes off to give that speed. They are often mounted in the fan motor cowling area as this keeps them cool, so may be a case of getting upside down under the dash area with a torch.
Roughly £9 on eBay, if you look at the picture you will see what to look for in car.

 

[BooBooDevere]

Thanks, will def get that swapped out with a new one