Mould Smell When Demisting Windscreen

[OKEH1]

I have a 2004 RX330, and live in California, the weather has recently turned cool and wet, and I now have a probelm witht he windscreen misting up randomly, I then operate the de-mister switch on the dash and within a minute the windscreen clears, but during this operation there is a foul mouldy smell , which fills the car , to such an extent now it is making us feel ill, and my wife and kids don't want to travel in the car ias it is starting to linger now.

Does anyone else have a similar problem?, the smell only appears when the demister switch is operated and not with the A/C. should I take it in for inspection?, any help greatly appreciated.

[wwest]

Unless you have had the dealer set the c-best option so that the A/C doesn't operate in demist mode, it will operate but with no A/C indicator lit.

It is my understanding that the RX330 has three options, disable the A/C from operating in automatic mode unless you enable it. It stays enabled through restarts until you turn it off. Disable the A/C form being "linked" to defog/demist/defrost mode. And lastly disable the climate control's automatic capability with regards to shifting out of footwell mode once the cabin temperature reaches or approaches the temperature septpoint.

This latter will help dramatically to prevent misting of the windshield altogether. Once the system shifts out of footwell mode absolutely NO warming airflow is routed toward the interior windshield surface.

See:

http://www.airsept.com/eed.html

for more information about mould and mildew.

Meantime it will help to lower windows slightly in the garage at night to let the day's accumulation of condensed moisture trapped on the A/C evaporator vanes evaporate and flow out of the vehicle. Or it wouild help even more to set the appropriate c-best option to disable the A/C entirely unless you want to use it to cool the vehicle and then not use it at all unless the OAT is above ~60F.