Moisture inside headlight assembly & stinky A/C

I can tell you from experience that this may not cause the bulb to fail prematurely, but so too will it cause your headlight assembly to fail also. "Curosion" is what it is referred to by my warranty folks and NO it is not covered. I am still arguing the issue, but so far I am facing a $504-$900 bill.

Slight moisture inside your headlight lens is not uncommon. The heat generated when the lights are on should cause the moisture to evaporate and dissipate out of the vent tubes. However, excess moisture can be a problem, there should not be a puddle of water in the bottom of the headlight assembly, that would indicate a crack in the housing and require replacement of the headlight assembly on your 2003 Acura TL. The best thing I have found for A/C orders is good old Lysol. Most times the smell is caused by mold on the evaporator core inside the heater box. Try spraying the Lysol into the fresh air intake - most often at the base of the windshield on the passenger side. Make sure the A/C in on and set in the fresh air mode with the blower on medium. Spray a generous amount of Lysol into the system. If this treatment does not work then the heater box may need to be removed and cleaned. The root cause of the problem the moisture created by the A/C evaporator. One way to help dry the system after use is to turn the A/C portion of the system off a couple of miles from home to help the system "dry out" before parking your car.

same problem here with an 03' tl type s. if you dont replace it, the inverter under the bumper will go out. costed me 300 to get it replaced

Moisture in the headlight can cause premature light failure. Most fixtures can be replaced without breaking the bank. The moisture occurs when there is a defect in the fixture, a crack, leaking at the seam, and some comes from the heat created and cause condensation. As far as the A/c smelling, that could be stagnant water in the HVAC box due a plugged or previously plugged drain. Part stores sell liquid you can poor in the vent, but that is a band aid, as any other "cover the smell" product when used. The right way to fix it, is to remove the HVAC box, clean, deodorize, and sanitize the box, and the problem will be solved. This is a good time to change the heater core, and evaporator core as its overlapping labor, and will save you from changing them at an inopportune time like when they fail, as opposed to doing it as maintenance when its convenient for you.