Question: I have a problem that nobody seems able to fix. The electrical circuit controlling the parking lights and dashboard lights on my 1973 Datsun 240Z will not turn off when I turn off the main headlight switch. The fuse heats but does not burn out. Instead, the fuse ends melt and separate from the glass tube. I have noticed the fuses for the headlights are also getting hot. The fuse box has been replaced twice, but the problems remain. Any ideas?--J.W.
Answer: The problem of an electrical overload in the wiring system would ordinarily be caused by something that had caused a short circuit or put additional resistance into the circuit. Typically, you could look to corrosion in connectors or frayed wiring to explain these problems.
But if you are correct about your description of the fuse ends melting but the fuse not burning out, you have some other type of a problem. First of all, you need to find out whether the voltage being put out by the voltage regulator is correct. Most 12-volt systems are charged with 14.5 volts from the regulator.
I would also check to make certain you don't have any obvious electrical shorts or electrical leaks. In the past, you could just turn off the engine, disconnect the clock and make sure no electrical current was flowing from the battery. But some of today's automobile electronics constantly draw small amounts of power, so you have to deal with that.
These two tests will probably turn out positive, assuming the car is working properly, except for the problem you describe. One important thing you should look into is whether the fuse box that was replaced was properly wired. Possibly you had one problem that was repaired or masked when the fuse box was replaced, but a new problem was created by an improper installation.
The fuses that are overheating but not burning out could be caused by current that is flowing through the fuse box in improper circuits and not crossing the fuse link. It is not clear why the fuse box is overheating in any case, and the fact that the fuses are not burning out could only mean that they are not wired as they should be.
You might attempt to see if any fuse, even one with a much lower wattage than suggested, will burn out.
Q: I own a metallic-maroon 1983 Olds Cutlass. The paint has become severely crazed. I have taken excellent care of the car, parking it in a garage and regularly waxing it. I took my problem to the local Olds representative who said the paint crazed because I took "too good" care of my car. He said a metallic paint should never be waxed. I am skeptical. What's your opinion?--J.C.
A: You are absolutely correct to be skeptical. Metallic paints usually age much faster than opaque paints, despite claims that things have turned around in recent years.
A metallic paint contains tiny chips of metal that create an especially lustrous effect. The problem is that such paints contain fewer pigments, which help give paint body and durability.
The crazing is the result of a clear coat over the paint beginning to degrade from ultraviolet rays and atmospheric pollutants. In addition, a faulty color coat can cause failure of the clear coat over it. Careful treatment, including waxing and storage of the car in a garage, helps offset crazing. But sometimes a paint job will fail despite the best care.
If an Olds rep told you that you took "too good" care of your car and ruined your paint by waxing the car, he was full of baloney. It's a sad fact that many modern auto paints are not lasting more than four or five years.