I suspect there are very stinky mushrooms growing in the debris inside the ventilation system. We live in Florida and the van sits outside in an area in our yard where stinky mushrooms grow at certain times of the year. I have tried spraying Lysol in the outside vent with the fan on full. That seems to have helped ove time but can I dump some vinegar in there without harming anything? Any other suggestions would be appreciated.
ventilation system stinks on 1999 Chevrolet Express 3500
I use bleach/water solution poured into the ventilation intake cowl area. Also try to physically clean any debris out of the system.