Suppose the ignition goes wrong and the battery seems to be all right and no cause of trouble can be found in the magneto and its wires, and the chauffeur is in a pickle. Along comes Mr. Man-Who-Knows and finds that the trouble is a short circuit in a lighting installation which impaired the ignition so that the cylinders would not fire, or fired irregularly.
The old cars did not have generators and motors; but the driver now must know how to sandpaper commutators and undercut the insulation of commutators, which is an electrical engineer’s job; and he must be wise enough to know that these things are necessary because there is sparking at the commutator, and the generator is not charging the battery as it should, and the motor is not starting the engine as it ought. This, of course, is because the brushes are overriding the commutators when the insulation is not undercut, and the contact period is shortened, and perhaps some of the contacts are skipped altogether because the high speed carries the brushes over without touching the commutator.
Then, he must know, for instance, that when the lights dim while the engine is going at low speed, it is because the reverse current cut-out is out of adjustment and it requires a considerable discharge from the battery into the generator in order to make the cut-out operate, when the lights will become bright again.
Also, he must know, when the volt or ammeter needle becomes erratic, sometimes showing a big charge or a little charge or no charge at all and then comes to normal again, that he has a loose connection somewhere or the voltage regulator is not working properly.
When he presses the button of the electric horn and it does not sound, but does work right after he has kicked or pounded it, he ought to know why his rage started it working. It was simply that the brush stuck upon a dead contact point of the commutator, due to a dead armature coil, and when he jammed the horn it moved the commutator until a live contact point was against the brush and the motor started to work.
There was a time when the manufacturer pointed with pride to the fact that there were no complications on his car. There was nothing on the dash but the ignition switch, with one wire leading to the magneto. This followed a period when the dash had been filled up gradually with all sorts of devices. Ways were found to do away with them.
Now there are hundreds of wires and pipes tacked on to the dash, and the other side of the dash fronting the driver is filled with dials and gauges and switches almost without number. These all add to the comfort of the motorist, but in the same proportion they add to the worries of the driver. He pays the price of the comforts in added worries. Owners also find that these added conveniences have given demand for added technical knowledge.
CHAPTER XLIV
DON’T TAKE THINGS FOR GRANTED
Don’t take anything for granted with your car. Don’t expect that there is water, or gasoline, or oil, or current in the battery, unless you have first inspected to find out. Inspect, don’t expect. There are many bad habits in car practice, and one of them is the evil of absent-mindedness in locating troubles in your car.
The man who spent half an hour looking for his glasses, and then discovered they were on his nose, should not be laughed at by anyone who runs a motor car. It is only natural that this man should take it for granted they were not on his nose, yet taking things for granted, writes Harold F. Blanchard, in Motor Life, is the greatest difficulty that the man who has to locate trouble has to face, whether he is an amateur or an expert. A number of cases are cited to prove the point.