https://forums.justcommodores.com.au/threads/air-conditioner-smell.273209/
Lots of threads on the subject really
Unfortunately our modern cars are not like our old cars used to be, where you could get a wire and push it up the drain tube to clear it and if that didn’t work you could get reasonably easy access to the core to clean it (older the car, easier the access)… Modern cars can be a PItA to service.…
But if your car leaves a wet spot when parked, with the ac running on a humid day, the drain is working ok so it isn’t the issue… If you don’t get a wet spot, the drain could be blocked or you’re doing something wrong or the car isn’t sexy enough
Basically, I’d start by changing your cabin filter or clean the screen filter (locate on the firewall and accessed from the engine bay). Make sure that intake area is nice and clean and drains ok.. And do note that if you’ve only got a screen filter, and especially if it’s torn, crap will get into the evaporator and it will get manky over time. If that’s the case, it will require lots of effort to get to the evaporator to clean any dust, fluff and mold from within the depths of the HVAC system under your dash…
@Fu Manchu wrote a how to thread on removing the HVAC unit on a VE/VF (= PITA job)…
If you can get the evaporator spotless clean, make sure to use a cabin filter and make sure to check it frequently and change it as needed (yearly?)… Such should stop too much crud getting inside the HVAC in the future. Unfortunately I’m not sure about how much crap can get into the system via the cabin recyled air intake which should really be also filtered, so keep your passenger and drivers floor clean would be my suggestion… Guess prevention is better than a cure
Whatever the case, moisture will still build up on the evaporator as is the case with all air conditioning systems. As such, the moisture can cause mold growth on evaporators. So consider having the “afterblow feature” enabled which helps to remove the moisture by running you fan for a while after the car is shut down which blows air through the evaporator to dry it out…
