Doug McAllister/Under the Hood: Mildew can grow in A/C system

Q. The ventilation system on my Infiniti G35 smells like a musty basement when I start the car and occasionally smells when the air conditioning is on. The car is garage kept and I don’t have a problem with leaves or other debris accumulating on the intake vent. The cabin filter is changed every 15,000 miles. It’s dry and doesn’t smell. Any suggestions?

A. The problem you are experiencing is common and can be resolved fairly inexpensively. Generally what happens is you get a bit of mildew built up in the heater/evaporator box under the dash. This is the area where the inside air is made hot or cold depending on the request.

The air conditioning evaporator is where a lot of moisture is created when running the A/C and is what generates the water that runs out of the car when the A/C is on.

First, make sure the water is running out of the car and not into the car. This can happen when the condensate drain becomes plugged with debris. After determining that the A/C condensate (water) is flowing out properly, you will want to buy a can of HVAC deodorizer from the auto parts store. There will be directions on the can but the idea is to spray the contents of the can into the intake for the A/C system so it can coat the evaporator and heater and kill all the mildew.

If you don’t want to fool with it yourself, most shops will handle it for you and it should be between $50 and $100 for chemical and labor. There is also a machine that some shops have that generates the mildew retardant and mists the entire cabin of the car to get rid of all the mildew in the car.

Brighter lights

I came out of a meeting the other night at about 8:30 p.m. and was surprised at how dark it was already. I guess that happens every year about this time and it got me thinking about the changing of the seasons, which is just about upon us and what that means for our cars. It’s time to start thinking about what needs to be done before we head into winter.

One of the things you will want to think about is lighting. Are all of the lights on your car working properly and are they clear? I have written about having the headlights refinished before. Don’t discount the diminished effectiveness of your headlamps because of the degraded plastic lenses.

Now that it’s getting dark earlier, you may be running a fair amount of your errands in the dark. I am always amazed at the poor condition of some of the headlamps I see on a lot of the cars on the road.

Take a close look at the headlamps on your own car; if they are not clear, you have reduced your night time visibility significantly. I would suggest that you have them refinished, not only will you be able to see better at night but the car will look a lot better as well.

Ÿ Douglas Automotive is at 312 S. Hager Ave., Barrington, (847) 381-0454, and 7218B Virginia Road, Crystal Lake, (815) 356-0440. For information, visit douglasautomotive.com. Send questions to underthehood@dailyherald.com.