CHAPTER XVIII

THE ELUSIVE “JUICE”

It takes good “juice” and lots of it to run a modern auto; not the kind that Uncle Sam has put a ban upon, for that ran the auto into the ditch oftener than most anything else; but something quite as hot and with at least an equal amount of “kick” in it—the electric “juice.”

Probably this is the least understood element in running a car, if one may judge by the troubles reported. Large numbers of autoists have no idea of the functions of the batteries and wires and switches and other parts of the electrical equipment, and when anything goes wrong they are helpless.

In dealing with the electrical equipment of a machine the owner should understand that a complete circuit is necessary in order to have the current do its work; that is, starting with the battery as the source, a wire leads the current from the battery through the switch to the device to be operated, and then the current must be led back to the battery before it will do any work. It is not sufficient simply to lead the current to the device; if there is no way back to the battery it will not get even as far as the switch. It won’t travel except on a round-trip ticket.

In looking for trouble electrically the first thing to inspect is the battery. See that it is charged—has current in it. That can be determined by using a voltmeter (for dry cells an ammeter) or a hydrometer. Then each successive terminal from the battery should be tested. For instance, there is a wire to the lighting switch. It is insulated and the first place to test after making sure that the battery is O. K. is at the switch. If there is no current there the wire may be broken or the terminal connections poor; but whatever the trouble may be, you have narrowed it down to one small stretch of wire.

The next step would be to test where the wire leaves the switch to go to the device to be operated. If the current gets to the switch and does not get out of it, it is apparent that the trouble is in the switch, or if it gets to the switch but not through the fuse, the fuse is at fault.

If the current leaves the fuse and does not get to the lamp which the switch controls, then we know that the trouble is in that wire somewhere; if it gets to the lamp but the lamp will not light, we know it is in the lamp; if we can trace it through the lamp, but it does not reach the battery, we know that it is the wire leading back to the battery which is at fault.

If the current is carried back through the frame of the car, as is very often the case, frequently the ground connections are poor or there is a break in the ground. Thus, we might attach a ground wire to a piece of iron on the dash, and if this is of wood that piece of iron might be insulated from the remainder of the metal work of the car and the ground connection would not be complete.

Recently the author came across some electrical troubles which were rather mysterious to the owners of the cars, but proved to be simple under systematic search. One man worked all of one Sunday morning, with the help of several sympathetic owner friends trying to find out where an extra wire on his switch should be connected. He could not get the engine started, the horn would not blow, the headlights would not light, the starting motor would not turn over, but the dash and tail lights, which were in series, did light.

A little experiment developed the fact that when the starting pedal was depressed the dash light grew very dim. This, of course, indicated that it was not possible to draw a very large amount of current from the battery, or that the battery was either in a discharged condition, or that the connections leading from it were poor. It was found that when the wire connected to the battery terminal was moved, the light would brighten up. This wire was disconnected and cleaned carefully to make sure that the contact was good. When it was assembled again no improvement was shown, so it was taken apart again and a careful inspection showed that one end of the taper on the inside of the terminal had a slight shoulder, which prevented the taper end of the wire from being drawn into place snugly. Therefore a very light contact was made and sufficient current could not pass to operate the starting motor. This shoulder was removed with a penknife and the engine started without difficulty. Several hours’ time would have been saved if the owner had started to look for the trouble at the source of the current instead of puzzling over the end of a wire that was not intended to be connected to anything and had nothing to do with the trouble. It was simply an extra wire for use if some new device should be installed.

A week later this same man was unable to start his engine and again worked over it several hours before calling for help. This time the lights were all right, but the engine would not start. To determine the condition of the battery, he turned on a light and depressed the starter pedal as before, to see if the light would dim very much under the heavy load; as it did not, it was decided that the battery was all right this time.

The hood was open and it was observed that when the starter pedal was depressed the fan did not revolve and therefore the engine was not being turned over, though one could hear the starting motor buzzing plainly. This showed that the overrunning clutch of the starting motor was slipping. As correcting this trouble was a shop job, they cranked the engine over by hand, but still it did not start.

To make sure that a spark was being delivered, the wire leading from the ignition coil to the high tension distributor was disconnected and given about 1/16 inch gap. As soon as this was done it was plain to see that a spark was being delivered, and the engine started immediately also. Making a slight gap in the secondary circuit increases the intensity of the spark at the plug and often aids in starting a balky motor. This was an occasion when an outside spark gap was of value. After the engine was warmed up, it was started several times without difficulty.

Another fellow who was in trouble had a “sick” horn. It sounded like a man who has a cold clogging his vocal organs—that is, it gave a cracking or rattling sound instead of a musical note, if the sound of a horn can be called musical. This type of horn has a notched wheel which revolves and strikes against an iron pin riveted into a disc. The disc in this way is made to vibrate, giving the desired sound. An examination showed that the pin had become loose and rattled. It was explained to the owner what the trouble was and he was told that the pin was of hardened steel and as it was rather difficult to rivet it, it might loosen up again. He replied that he would not worry about that, because now that he knew what the trouble was he could easily get it fixed again or replace it if necessary.

Another fellow had a horn which would not play because it had become grounded and blown the fuse. The ground was removed, but as no fuse could be obtained, a single strand of very fine wire from an ignition cable was substituted in place of the fuse. This wire was small enough to burn up before other short circuits could do damage to battery or wiring.

Still another fellow had his car laid up for a week while he tried to find out what was the matter with it. He had sent magneto and coil to the factory for repairs and when they were returned to him a new type of coil was provided. He wired it up the best he knew how, but the engine would not start. Checking the wires over very carefully, they seemed to be placed properly, but a spark could not be obtained. Going to the source of the current, a test of the dry cells with an ammeter showed that they were dead. The fellow had lost a week’s use of the car because, having decided that the trouble was at the magneto or coil, he did not look anywhere else. He should have started at the battery to trace the current.

Another case which came under notice was where one of the headlights failed to light. A test showed that the current came to the lamp. To make sure the lamp was not at fault the one from the opposite side was substituted, but it would not light. The lamp was grounded by an extra length of wire and it worked all right. Then it was found that the ground wire, which was located back of the reflector inside the lamp, had become loose.

Most of these troubles point to the fact that a complete circuit is necessary to have an electrical current do its work. Therefore, when trouble occurs, the source of the current should be examined first and then the current should be traced through its entire path leading from and returning to the battery.

It might be a good idea for the owner on winter evenings to get out the wiring diagram of his car and trace the current from the battery through each light, through the ignition system, through the horn, and through every other electrical device used on the car, including the generator and starting motor.

Also it might be good practice for the owner to carry his wiring diagram with him when touring, so that the garage man, if there be trouble, may be helped to quickly locate it. But if the winter evenings be spent wisely in studying the electrical equipment, or even the entire car, or perhaps invested in a course of instruction at a good school, the owner might be independent of the garage man for the most part and besides have the satisfaction of knowing that when anything does go wrong he can find it and in most cases fix the trouble. The release from worry ought to be worth the time spent in learning how.