Q: I have a 2004 Ford Focus. When my car sits in the garage for a couple of days some of the dash lights and dome lights will stay on and there's a beep, even with no key in the ignition. I start the car, the beep stops and the dome light goes out but the dash lights stay on. The next day everything is OK, then the cycle starts all over again. Any ideas?.

A: Strange electrical gremlins like this often are hard to pinpoint but in this case I think the ignition switch and/or lock cylinder are the likely suspects. My ALLDATA automotive database pulled up Ford bulletin No. 05-21-17 dated October 2005 that outlines service procedures for replacing the ignition lock cylinder if the ignition chime beeps with the key removed. There's also a troubleshooting guide for continuity testing of the ignition switch at its multi-terminal connector.

I'd suggest locating, disassembling and cleaning the multi-terminal switch connector under the dash to see if this restores proper switch function. If not, it's probably time for a replacement.

Q: I own a 1996 Toyota Camry V6 with 300,000 miles. We have a problem with the car vibrating when I step on the brake as the speed slows from 25 to 15 mph. The harder I brake, the worse the vibration. If I shift into neutral the car will not shutter or vibrate. Two other interesting things occurred at the same time. The check engine light came on, and when I step on the brake both the "Reverse" and "Drive" indicator lights are on. The car has no trouble shifting. My guess is that the torque converter is failing. Your thoughts?

A: If the torque converter were failing to disengage when the brakes are applied, you would experience a shuddering as the vehicle slowed to a stop. In fact, the engine would stall as you came to a complete stop, just as if you'd left a manual transmission vehicle in gear and braked to a stop.

Since the shudder/vibration is occurring in a higher speed range, my first thought is that the transmission has failed to downshift as the car slows. Try driving with the transmission's overdrive switch off to prevent the overdrive from engaging. Then try manually downshifting through each gear, matching the gear to the road speed as the vehicle slows. You could also try downshifting to third or even second as you're experiencing the shudder in that 25-15 mph range. If any of these tests stop the vibration, the problem is most likely in the transmission itself.

Have a scan tool read the DTC fault code that triggered the check engine light, but with 300,000 miles on the vehicle, the only transmission "repair" I'd suggest would be adding half a can of SeaFoam Trans-Tune to the fluid to clean any sticky solenoids or valves in the valve body.

Q: The maintenance schedule for my 2003 Toyota Avalon has me replacing my iridium spark plugs at 120,000 miles. At 130,000 miles, the car runs fine and this plug replacement is expensive. Is it necessary?

A: Why does this question remind me of doing my taxes or making a doctor or dentist appointment? All of them are no fun at all, but necessary if one wants to stay law-abiding and healthy.

So yes, you should follow the manufacturer's recommended spark plug replacement interval, particularly if you're going to keep the vehicle for several more years.

With that said, I'd be more concerned about one or more spark plugs ending up seized in the cylinder head as they are removed. I've always been a fan of removing the original spark plugs at 10,000 to 30,000 miles, coating the threads with anti-seize compound and reinstalling them for the remainder of their full service life.