DEAR CAR TALK: With all these things we are plugging into our lighter sockets these days -- phone charger, GPS, radar detector, you name it -- we end up with these lighter-socket plugs sitting there all the time with glowing LEDs on them. My question is: Do these LEDs draw enough current to pose a threat to my battery's life? Should I be pulling them out every time I leave the car overnight? I do that now, but it is a pain for sure. What do you think?
-- Alan
DEAR ALAN: Well, a lot of cars will cut off power to the power ports (what we used to call "cigarette lighters") when you turn the car off. So it's not an issue for most people.
If your car is one of those that continues to power the outlet even when the car is off (so the green LED light stays on), then yes, you are using battery power overnight to light that LED.
Fortunately, it takes so little current to light that LED that your battery will power it for ... let me do the math ... between 2,500 and 2,700 years before it's unable to start the car -- an LED that size takes an infinitesimal amount of power. The digital clock in your car takes more power.
Of course, if you leave your car sitting for a month, it's likely that the battery will get drawn down. But that won't be from the LED lights on your charger; it'll be because things like the car's computer and evaporative emissions system draw power even when the car is parked.
Great! Now you're going to stay up nights obsessing about how much power your evaporative emissions system is using!
Actually, if you've got several devices, and it bothers you, another option is to get one of those power-outlet adapters that turns one outlet into several. Then you can pull out that one plug when you leave the car and disable everything.
But even that's not necessary. So free your mind. Don't worry so much. Try to imagine that you're just providing a nice little nightlight for all the spiders living in your upholstery. Does that help?
DEAR CAR TALK: What are your thoughts on replacing a water pump, alternator or other components before they fail? I have a 2000 Corvette with 84,000 miles that we are planning to take on a caravan this month from the Pacific Northwest to Bowling Green, Ky. I have not had any problems to date, but I wonder if taking preventive actions now, before a problem arises, is advisable? Thank you.
-- Lee
DEAR LEE: I love the idea of replacing parts before they fail. But then again, our shop is full of mechanics trying to put their kids through college.
Practically speaking, I actually don't think it's a good idea. With 84,000 miles on the car, anything could be a candidate for preventive replacement at this point. You'd be taking wild guesses. Why not replace the fuel pump, too? How about the brake master cylinder? How about the engine?
And when you tell a mechanic that you want to start replacing parts that are not showing signs of failure, you also open yourself up to unscrupulous operators who may be more interested in running up your bill than in keeping you out of the breakdown lane.
So instead, ask a mechanic you trust to do a thorough inspection of your car. If he sees actual evidence that a part is faltering -- if he hears the water pump making noise or sees some wobble in the water pump pulley, or if he hears the bearings in the alternator making noise -- then you can legitimately replace those parts, and consider it evidence-based preventive maintenance.
Or if he works on lots of older Corvettes, he may have developed some specific knowledge about certain parts that tend to fail on the car at 90,000 or 100,000 miles. That also can be considered evidence-based preventive maintenance.
And then give yourself a few extra days to get to Bowling Green. Put aside some money for a few motel nights in case you do happen to break down; that's a risk you take when you drive a 15-year-old car across the country.
But if you have a few extra days to get there, then it won't be so stressful -- it'll just be part of your adventure: You might get to spend an unexpectedly delightful day (or three) exploring the Museum of Belly Button Lint.
Ray Magliozzi dispenses advice about cars in Car Talk every Saturday. Email him by visiting
cartalk.com
HomeStyle on 08/22/2015