Any ideas on what could be causing a pungent odor that comes from the a/c vents?
Smells like a fish or rat died in there. Does not happen all the time. Have tried it with outside air, vent, and a/c.
If the evaporator drain tube is clogged water will puddle and mold will grow. It’s also possible that something DID die in there. Happens all the time. Check the drain tube first.
This is most likely mold in the evaporator case.
First, unclog the evaporator drain in the engine compartment. It’s at the firewall.
Then you may need to disinfect the case. This is accomplished by purchasing a special can of disinfectent spray at an auto parts store. It ususally comes with a long hose. Insert it into the floor vent nearest the evaporator and spray towards the evaporator. Try to move it around to cover everything. You can even remove the blower fan in the engine compartment and spray from there too.
That will eliminate the odor.
-Matt