Loss of headlights more than just a bulb problem
Q: We love our 2007 Prius and we have 217,000 miles on it. About two months ago, I was driving at night on unlighted neighborhood streets
and both of my headlights went off. It was pitch black. I toggled the light switch off and on and the headlights came back on. This has happened several times since. We called several dealers and repair shops. They all said to replace the headlight bulbs. Now, if one would go off, I would agree. But both at the same time? I would say it has to be some control that is common to both. The loss of headlights happens randomly. I even looked through a schematic diagram for headlights, and there are several components that are common to both headlights. The simplest one appears to be a ground to chassis, but I am definitely not a mechanic, so I cannot even try to locate it. Have you heard of this problem and the fix for it?
A.H., Chicago
A: Since toggling the lights switch brings the headlights back, it sounds like a circuit breaker is the problem, but not the underlying cause. If there is an excessive current draw, the breaker will open. When it cools down, the circuit closes and the lights work — temporarily. By switching the lights off, you are allowing the breaker to cool. Unfortunately, I can’t guess what that root cause is so you will have to have a technician troubleshoot it.
Q: Are mud guards worth it on new cars? Do they prevent rust on the body behind the wheels? Do they reduce the miles per gallon? J.C., Oak Grove, Minnesota
A: Mud guards do not affect fuel economy. And they usually don’t contribute to rust, especially if they are installed properly. They do, however, keep mud off the fenders and sometimes the rocker panels, so you may be less likely to soil your jeans getting out.
Q: In response to the question about transition (more properly photochromic) windshields. I was a licensed optician for almost 40 years, so I can cite several issues. Transitions always have a slight residual tint. Transitions darken fairly quick, but take about four times longer to lighten. Enter a tunnel and you’d probably be all the way through it before the windshield lightened. They are temperature-sensitive and don’t work as well in hot weather. Not everyone likes transitions. In my experience, most tried them once or twice and then went to a clear pair of eyeglasses and a pair of sunglasses. And finally cost. Transition lenses have millions of silver halide crystals in them. Detroit loves to save pennies, not spend hundreds. W.G., Waterford, Connecticut
A: Your response to my reader’s question asking why carmakers don’t offer transition windshields is an eye-opener. Here’s another nugget: Mrs. Motormouth is nearsighted in one eye and farsighted in the other. When she asked about transition lenses, the optometrist told her it would not work.
Q: On this past Sunday’s issue, you mentioned the “B” pillars. Methinks your description is the “A” pillars. Or maybe I’ve been wrong for a half-century or more. At any rate, I’ve always thought that the pillar holding the windshield is the “A” pillar. Keep on writin’.
P.C., Elizabeth City, North Carolina
Q: In your reply regarding drain tube in your column, you indicated B pillar as between windshield and door frame. That would be the A pillar. Always good dialog in your column.
D.M., Chicago
A: I might try making up some excuses, but the only one that holds water is a typo. Otherwise, I may have to go back to kindergarten and relearn my ABCS. The dialog with my readers always keeps me on my toes. Thanks.
Bob Weber is a writer and mechanic who became an Asecertified Master Automobile Technician in 1976. Weber’s work has appeared in professional trade magazines and various consumer publications including Consumer Guide and Consumers Digest. Send questions along with name and town to motormouth.tribune@gmail.com.