Q I have a 2003 Mazda MPV that still has the original battery. How long does a typical battery last? The MPV has 110,000 miles on it, and I drive it about once or twice a week. I suppose I can expect it to fail now that I have shown it some attention and written to you about it.

A Not only has it lasted significantly longer than typical -- three to six years -- I suspect you're now on borrowed time with the battery. Batteries always seem to last until, well, you need them most. You can have the battery load tested to determine how many amperes of current it can deliver to crank the engine, then compare that to its original rating. I suspect it will be at something less than half of its original capacity.

The good news is that today's computer-controlled, fuel-injected engines don't require as much help from the battery. But with winter here, if the battery doesn't deliver more than 75 percent of its original starting capacity, I'd replace it now.

The price of a new battery is a mere fraction of the cost and inconvenience of a dead battery at the wrong time.

Q There is a constant clicking noise that comes from the central area of the instrument panel of my 2003 Pontiac Grand Am. It sounds like the turn-signal flasher unit turning on and off. The turn signals don't flash while this is happening, but the sound disappears when either turn signal is actuated.

I found an article online that said this sound is caused by a contaminated multifunctional switch. It said to remove the multifunctional switch and clean out all excess lubricant, reinstall the switch and problem will be solved. The dealer mechanic told me the switch was sealed, so the only solution would be to replace the switch for $500.

A According to my Alldata automotive database, the repair time for replacing the multifunction switch in your vehicle is 1.1 hours, and the switch price is about $240. In addition, the air bag has to be safely disabled while replacing the switch. You might price this job from an independent shop and ask if they can fix the original switch. The problem, of course, is that if they clean the switch but it develops the problem again, who's responsible?

Q I have a '99 Audi A6. Last December I had the front brakes and rotors replaced. Recently, my local mechanic couldn't rotate my tires because one of the lug nuts was stuck. He claimed it was cross-threaded and that I should take it back to the brake shop. The brake shop couldn't get the lug nut to budge either and claimed that it is most likely rusted on. From what I understand, getting the wheel off will most likely damage the rim beyond repair. How can I dispute the claim that the lug nut is rusted on vs. cross-threaded?

A Don't give up yet. I've never seen a lug nut that was so rusted on that it could not be removed. Years ago I tried to remove the lug nuts on my M37 three-quarter-ton military truck. The huge lugs hadn't been off in decades, and I couldn't budge them with my half-inch drive impact wrench. I managed to get one off by heating it with my oxy-acetylene torch before I got smart and took the truck to my local truck repair shop. They had a three-quarter or one-inch drive impact wrench that spun the lug nuts off relatively easily.

So, like Tim the Tool Man used to say, "more power"! Because of the alloy wheels, heat might damage the wheel. Worst-case scenario would be to break off the stud to remove the wheel, then install a replacement wheel stud.