Q. I read your column every Sunday, and find that it is very interesting and educational.
My question involves why an intermittent, shorted-out speaker in the right rear door of my 1993 Lexus would continually drain the battery overnight, when both the ignition key and the radio are always turned off. I am presuming that the speaker is shorted out, because I can hear it buzzing sometimes and, when I removed it, everything worked fine.
The dealer and others were no help, but maybe you could clarify the problem for me.
A. If the speaker were shorted, it would make no noise at all. Shorts usually blow fuses.
Something is draining current from the battery when the car is parked. This is usually easy to determine: All you need to do is to get a meter to measure the current flowing from the battery.
Normally the reading would be 20 to 30 milliamperes, enough to keep the radio presets, clock, and engine-computer memory alive. If it is substantially more, something is still turned on.
Simply remove the fuses from the fuse box, one at a time, until the current drops. Then you can disconnect devices from that circuit, one at a time, until you figure out what is still on.
More than once I've had to climb into the trunk and have someone slam the lid shut to see if a trunk convenience light was really going off, the same way the light in the refrigerator does.
Q. I have a question about front-end camber (wheel) adjustment on my 1990 Nissan 2WD truck.
How do I readjust a positive camber back to neutral? It's looking vertical inward at bottom. The truck has visible tire wear on the outside.
There aren't any shims to remove. I'm worried that I may lose vertical ride height or cause a stiff ride if I let out the torsion bar. The wheel assembly is not racking or loose on the ball joints, and there are no asymmetric upper A-arm bolts to adjust.
I'm scared to take it in after having received three recommendations by repair places, including placing shims front or back to bring it up to neutral again.
A. I'm assuming that the ride height is symmetrical and correct, and that the caster is properly adjusted.
If you can't remove any more shims from the upper-control-arm pivot, my guess is that you have a bent spindle, from whacking a pothole or curb.
You could remove the front discs and compare the angle of the spindle to a new one.
Q. Back in February you responded to a reader who said that he was getting little or no heat from his small engine. You stated that the water pump was probably not circulating enough water at idle to push or maintain the heat.
I have the same issue with my six-cylinder Dodge Dakota. Out on the highway I have to turn the heat down or open a window, but around town the snow on my shoes won't melt, no matter how long I'm driving around.
I have checked for vacuum leaks, changed the antifreeze and thermostat, etc. I have had the dealer and a friend who is a mechanic look at this, and no one has solved the problem or come up with a good reason for it. You are now the first person to come up with a very logical reason.
Now, what do you propose as the solution? I have tried to locate higher-temperature thermostats, but it seems they quit doing that some time ago. I can't put cardboard in front of the radiator, as I do go out on the highway often, and would not remember to remove it before starting.
Do you know of anyone making larger aftermarket water pumps?
A. When I Googled the words "car electric booster water pump," I got several product listings. I can't endorse any of them, but I'm sure there are others as well.
Mike Allen is a senior editor for Popular Mechanics magazine. Questions should be sent via e-mail to driveit@nytimes.com.
