News and Reviews

What’s wrong with my Mustang’s AC?

John Paul, aka “the Car Doctor,’’ answers readers’ car-related questions.

Q. I have a 1997 Ford Mustang and the air conditioning will not blow out of the dash vents. When I turn it on the air only blows out of the defroster. Do you know what I need to do to fix it and how much it will cost?

A. The heater air-conditioner system uses a series of vacuum controls to operate the duct system. For safety reasons the defroster setting works if there is a vacuum loss. Since the defroster is working the problem is a loss of vacuum. The problem could be as simple as a vacuum line leak.


Q. I have two cars: and I wanted to check the brakes. The front disc brakes were easy but I can’t get the rear drums off. Although the drums spin, I can’t get them off. Do you have any suggestions on how to do this without parts flying off or breaking something?

A. In both cases the brake drums won’t slide off due to a ridge of rust on the brake drums or the drum is rusted to the hub. First try penetrating oil such at PB-Blaster and allow it to soak in to dissolve the rust. Then using a heavy hammer strike between the lugs to break the drum lose. You also may back the brake adjustment off to permit enough clearance to allow the drum to slide off over the brake shoes.

Q. If I were to buy an electric car, I would most likely install a charger in my garage. What amperage circuit is required and what about the connector? Can I just charge it with a normal outlet plug and would something like a dryer connector and plug work? Have you driven an electric car lately?

A. Today’s electric or plug-in hybrids use a standard 120 volt convenience plug or a dedicated and standardized 240 volt plug and charger. Chargers are available through a variety of sources and will generally require a 30/40 amp circuit breaker. This is not a DIY project; my suggestion would be to have the charger installed by a licensed electrician who has received training on this type installation. Recently I was driving a Kia Soul E/V and it had a 105 mile range. The car was a great car to drive and performed well but charging was best performed with a 240 volt charger. As an example I live about 48 miles from work, with the range of the Kia I was able to drive to work and home and still have a few miles to go. When I plugged in the 110 volt charger it took about 16 hours to fully recharge the battery. If this was a 240 volt charger the car would have been fully recharged in four to five hours. Kia also included a direct current “fast-charge’’ port which can recharge the battery to about 80 percent in 30 minutes.


Q. I recently pulled into a gas station that was out of regular fuel and offered me premium at the regular price. When I asked about the benefits of premium the guy at the station told me I would be better fuel mileage. When I checked the mileage I didn’t see any difference, what is the real story?

A. The result you saw was typical, if your car is not designed to use premium fuel it is unlikely you will see any benefit from using it. If your car is designed to use premium and you use regular you could see reduced fuel mileage and performance as well in some cases possible engine damage.


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