Bad smell, like wet mouldy smell coming into cab via vents

[knakkers]

Hey guys,
today while out for a drive, I noticed a bad smell, like a wet mouldy, smell coming into the cab via the vents. (it's a smell like, when ur wife has left the wet washing in the washing machine for a couple of days before she hangs it out to dry)

When I turn the fan "on" the smell increases, but when I turn the air cond ''on'' it goes away. Then when I turn air cond "off" again the bad smell comes back again. (Damn it stinks). The smell is there if fresh air is coming in the vents, cool air or heater "on". Makes no difference which cycle I put it on, the smell comes in, Except when air cond is on.
Even when I lift the bonnet I can smell it slightly. There is no water leaks anywhere that i can see.

Thinking a heater hose may of split, I checked the front carpet for any dampness, can't feel anything. I changed the vent controls to defog the front wind screen to see if there was any moister on the front wind screen none, but the air is warm that comes out of any vent

Can anybody help? Any suggestions, on what could be causing this?
This smell only started occuring today.

Thanks guys

[marquis]

Your A/C evap coil is growing

There best option is to purchase a can of anti-mould(?) spray (not sure on the name of it - but it's about $60(wholesale price?) for a small can) from a car a/c specialist.

You have to spray it onto the evap coil located in the dash - and the smell will disappear (it kills the growth)

If your near Gympie QLD - I know someone that is good - but else where not sure.

[mrbitchi]

If that doesn't fix it then your heater core could be leaking. Test by bypassing the core in the engine bay. (re route the heater hose)

[Pagey]

I know of guys who used to piss in the grill under the windscreen where your fresh air is drawn into the cabin. Great party gag for the young blokes but would stink your car out to high heaven. Been to any parties lately?

[knakkers]

I know of guys who used to piss in the grill under the windscreen where your fresh air is drawn into the cabin. Great party gag for the young blokes but would stink your car out to high heaven. Been to any parties lately?

Have not been to any parties lately,(not ones where young ferrals go to anyway) & Paj always looked in garage. Somehow, I think thats not the reason for the smell..

[Jaydee]

I know of guys who used to piss in the grill under the windscreen where your fresh air is drawn into the cabin. Great party gag for the young blokes but would stink your car out to high heaven. Been to any parties lately?

few prawns or mussels poked down theirs with kebab skewers would return the favour.

[Pagey]

Not always young ferals do these sorts of things, as Jaydee says it happens but I hope this is not the case for your vehicle.

[grahamnb]

Do you have male cats in your house or in neighbour hood. Often get cats sprying on windsheild or vent area. The reason you don't smell it when aircon on is your aircon is recycling the air inside the cab not bringing in fresh from outside