TURNING ON YOUR AIR CONDITIONER TO MAXIMUM OFTEN MAY CAUSE BACTERIA GROWTH DUE TO THE EXCESS WATER THAT IS DRIPPING IN YOUR UNIT'S TRUE THAT IN HIGH HUMIDITY ENVIRONMENTS THAT MOLD CAN BUILD ON EVAPORATOR COILS AND CAUSE AN ODOR, ESPECIALLY IF THE VAN SITS FOR A COUPLE OF DAYS BETWEEN DRIVES. I MAKE IT A PRACTICE OF TURNING OFF THE A/C THE LAST FEW BLOCKS ON THE WAY HOME TO BLOW SOME WARM AIR THROUGH THERE TO DRY IT OUT A LITTLE IN THE SUMMER. NONETHELESS, IT IS ALSO POSSIBLE THAT YOU HAVE A DIFFERENT PROBLEM, ESPECIALLY IF ONE OF THE SMELLS YOU DETECTED WAS "VINEGAR." I WONDER IF MAYBE A SMALL ANIMAL/RODENT FOUND THEIR WAY INTO YOUR SYSTEM AND GOT STUCK AND HAS SINCE EXPIRED? IF THE SMELL IS ONLY THERE WHEN YOU FIRST TURN IT ON AND THEN DISSIPATES, THEN THAT SEEMS A LOT LIKE A COMMON MOLD GROWTH SCENARIO. IF IT PERSISTS, IT IS POSSIBLE THAT YOU HAVE A BIGGER ISSUE. *TR