FORD VAN POINTERS.
Page 24
Page 25
If you've noticed an error in this article please click here to report it so we can fix it.
By R. T. Nicholson (Author of "The Book of the Ford ").
IHAVE already told you what to do when the ammeter does not register with the engine mining—carry a safety wire from genera.tor terminaI to engine to" earth " the generator current, so that it may not strain the. generator internally.
228.—A Vicious Circuit.
There is another reason wily you should take. this ,. precaution if the ammeter does not register " charge " with the engine running If. the failure of the ammeter to register is dae:to•an interruption in the generator battery .circuit between ammeter and battery, and you switch on your lights in such circumstances, the -bulbs will burn out almost. at once. The reason why they do' so is that they are, in such circumstances, put into direct. connection with the generator if generating), directly the lights are switched on. • The current then travels by the "vicious circuit" shown in Fig. 152. The filaments are not strong enough to carry the direct generator current, and's° the bulbs blaze brilliantly for one glorious moment, and then give up the ghtast., The " vicious circuit" is, in point of fact, always.
open to the generator current when the lights are switched on—I mean, when everything is in order— but the generator current does not take that circuit if thereTis connection between generator and battery, because the latter line is the " line of least _resistance," and electricity alwaYs takes-the line of least, resistance. But if there is no connection between generator and battery the current takes the " vicious circuit " described, directly any of the lights are switched on.
Until the lights are switched on in such circumstances, the ammeter will • not register, simply because the generator battery circuit, as well as the "vicious circuit," is interrupted. But directly the lights ale switched on, the ammeter registers, and " up goes the donkey," so far as the 'lights are concerned. Then, of course, the ammeter again goes on strike, the " vicious circuit " being internipted by the burning out of the filaments.
The uninformed driver shoves in his spare bulbs, switches on the lights, starts her up again; there is. another momentary blaze, and out go the lights again—done for. Now, bulbs cost money in these haxcl times, so there is good reason why you should know a bit. about your electricity and its wily sways.
This trouble (due to interruption) may happen in any of the following circumstances, with lights switeled on.
Battery not in position.
Battery + or — clatn.p off battery. Battery eor -clamp off its lead. + or lead broken.
— lead off frame connection.
+ lead off foot switch terminal, or broken internally. .
Yellow wire off foot switch terminal or broken.
Yellow wire off terminal block terminal.
Yellow wire off ammeter terminal.
• This trouble will not happen in such ciren-mstances, if you run the safety wire from generator terminal to "earth " when the ammeter does not register, because the current will then not pass through the am meter on its way to the lights. But, on the otner hand, you will not 4ae able to switch on your lights at all until you have cured the interruption ;.because the interruption will also cut out the battery lighting circuits, Fig. l2 illustrates the trouble only as affecting the "bright " headlights, but just the same thing will happen to the " dim " lights when .switched on, and to the tail light ineither event. This trouble is not peculiar to the Ford • equipment ; it happens with most systems in which a generator (or dynamo) charges a battery which supplies (or should supply) lighting current.
229.—Open Coil Boxes.
I wonder why I see so many Ford vans running with the lid off the coil box ? . • There must be some unknown use for those coil-box lids—perhaps in the domestic circle—that I do not know of, or they would not be "left at home" so often. At all events, whether that is .so or not, the lid is very often spicuous by its absence. con Which is all wrong: Dust is not good units. Have you ever noticed that one of the contacts — the one on the upper "bridge --is mounted on a cushion spring. That spring is intended to act as a spring, and if the space behind it gets choked with duet it will not act as a spring. _ Then the ignition is apt to become uncertain.
A Dust, by toe way, should be washed out from behind the spring with petrol. It you try to sweep it out—even with a piece of thin .
paper—you are quite likely to bend upset its tension/
Fl;. 153.-11 is important to keep the space behind the contact springs of the coil free from dust.
the spring and 230.—Accessibility.
" Accessibility " is a beautiful word. It means so much—to the man who has to make running repairs. Generally speaking, I have no • quarrel with the -accessibility of the Ford working parts that may call for adjustment on the road, or on the round. But I was never in love with the position of the carburetter on the old style Ford—by which I mean the model that was standard before the present " selfstarter" model came on to the market. It was. tucked away on the right-hand side of the vlinder block, just under the steering column, where it simply could not be got at. Many a time I have said hard things when I wanted to turn the4carburetter drain cock—and you sometimes do want to turn it, to,get the dirt out of the oarburetter. You have to get your wrist at so sharp an angle that you begin to try to remember what mother told you was good for cramp ; and after that you begin to wonder ifeyou will ever again get your hand out of that awkward position into which you have managed to force it. Do you know why they put the carburetter into that position? The truth is that there is nothing the matter with the position of the-carburettor; it is the steering column that is inithe wrong placeIn American Fords, the steering column was, of course, always on the other side of the engine—the left-hand driving position being what they call "right " in America. So, there was plenty of foam for the carburetter in American Fords, there being nothing to pen it in. The carburetter control rod ran from the left-hand side of the engine, through that opening between the second and third cylinders which you will find on English Fords, and so to carburetter. I suppose that that opening was actually left as a means of passing the carburetter pull-rod from left to right. It was fairly simple to bring the drive over to the right in the English model ; but it was not at all simple to take the carburetter over to the left, ,o as to prevent overcrowding. That would have Meant big alteration in the construction of the Ford engine ; and the Ford people do not readily alter their designs : indeed, they could not do that with out increasingcost of production enormously. On the latest power-starter model, the carburetter has plenty of room round it. It's child's-play:go adjust it—to dicker with it—even to take it right out of position ; whereas, in the old mod-el, it was a rcgular Chinese puzzle to get that carburetter out_ At one time, it used to seem to me as if I should never get it out without taking the whole engine down.
So there is one advantage in the left-hand drive, anyway. I doubt if there is any other, though I am bound to admit that, after .a little experience, the left-hand drive seems to come as naturally as the old right-hand drive on which we , Britishers wera brought up.
231.—An Unexpected Circuit.
You know that you can start your latest model Ford on battery current. Possibly you do not know that, if you keep your ignition switch set to " Bat." position, the engine will not continue to run on battery current, notwithstanding the position of the ignition switch, but will actually run on generator current, once the geoerator is running fast enough to charge the battery. In point of fact, the battery will only supply current directly for ignition in actual .starting. Once the engine haa started, and the ammeter gets well over into " Charge," 'it is the generator that directly furnishes the ignition current in such circumstances.
You nekl, therefore have no fear that you are making any gonsiderable . draft on the battery by continuously 'keeping your ignition switch at ." Bat." position. All that happens is that irart of the gene' rater current. is diverted to the ignition from the battery.
In point of fact, this i(rnition circuit is alniost exaotlyzidenMeal with ,the magneto ignition circuit, except that the generator is 'substituted for the magneto, and furnishes continuous instead, of alternating -current. In practice it does not matter, for ignition r poses', w h e th er currezt js a 1 ternatmg or continuous.
The " unexpe ete'd circuit 7 in o tie s Con is shown in Fiv. 154.