From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Article on car maintenance covering starters, fuses, and headlamp focusing.
| Identifier | ExFiles\Box 160\3\ scan0229 | |
| Date | 10th February 1939 | |
| February 10th, 1939. The Autocar 215 LOOK AFTER YOUR CAR (CONTINUED) the brakes off, and the engine, of course, also switched off, the gear lever is placed in top gear position, and the whole car jerked back and forth by pushing and pulling. Usually this brings the jammed pinion free in a second or so; but in really obstinate cases, or if the car is heavy, it may be necessary to slack off the starting motor in its mounting. A fruitful cause of sticking starters is the irresistible attraction presented by an exposed pinion—if the starting motor is not of the enclosed pattern—when one is going round with the oil-can. Oiling the pinion and its quick-thread shaft produces excellent results until the oil collects dirt; then the inevitable happens. A squirt of paraffin on the pinion shaft is the cure. In discussing the dynamo, reference was made to the field fuse, which protects the instrument from excessive output. This fuse is clearly indicated in the fuse box, and a spare ought always to be carried in the socket generally provided for this purpose. In addition to the dynamo field fuse, there are various other fuses also in the junction box, the circuits they protect being indicated by the legend “S & T,” for the side and tail lights, and so on. A Foolish Practice Some people, when a fuse blows repeatedly, do nothing beyond fitting a new one and hoping for the best. This attitude is as nearly as stupid as that of the man who replaces the blown fuse with stout copper wire, and then wonders why his car catches fire! Obviously if a fuse blows repeatedly there is something wrong, and the particular circuit affected must be very carefully examined. Suppose that the “S & T” fuse referred to has blown. First have a look over the wiring of the side lamps; sometimes the armoured wire, which is perhaps brought up to the lamp by cleats retaining it within the wingstay, has broken loose, and is flapping about under the wing. Friction may have severed the insulation, and caused an intermittent short circuit. This is easily cured by cleaning the wire, wrapping the bared portion in insulating tape, and refitting the wire to its cleats. “Trouble-shooting” amid the wiring of a car is, mercifully, made fairly simple by the adoption of colour codes. Different shades of insulation on the wires, and coloured “tracers” enable each circuit to be followed out from junction box to extremity. One often wants to fit an additional accessory; say a road- or pass-light. Remember then that there is nearly always a special terminal provided in the junction box to enable extra fittings to be wired into a proper fused circuit. If this provision is used, check can be kept on the amount of current consumed, since it will register on the ammeter. It will not do so if a direct connection to the battery is made, and one can be completely and disastrously misled in estimating the demand that is being made on the battery. Lamp bulbs can fail at awkward moments; it pays to have a case of spares in the tool locker. A case, because glass bulbs do not travel happily with spanners and the like. When a head lamp bulb fails, unless one renews with exactly the same type of bulb, much trouble may ensue over the focus of the light. One knows that the difference between two branded bulbs of the same specification will not be enough to affect the efficiency of the lamp; but a cheap bulb may have its filament in a different position. Focusing Head Lamps To focus a pair of head lamps properly, one needs to have the car on a flat, plane surface, dead at right angles to, and about thirty feet from, a truly vertical surface—preferably whitewashed. There should also be guide lines on the wall, and then the matter becomes comparatively simple. Comparatively, because there are many headlights to-day which cannot be altered as to reflector-bulb focus without taking the whole reflector out every time. However, focus apart, there is much that the amateur can do to preserve a good driving light—and avoid annoying others or breaking the dazzle laws. The headlamps should be left unopened as long as possible, since dust and damp are the mortal foes of the silvered reflector. When it does become necessary to remove dust from it, a perfectly clean, soft chamois leather, or in emergency an old, soft silk handkerchief, should alone be used. Sometimes, when the car has to be moved by hand, the headlamps offer a most inviting grip, and many who ought to know better can be seen to move the car by the lamps. This may cause the lamps to shift a fraction of an inch on their mountings, and next time the lamps are used the beams will light the tops of the telegraph poles. This may also render one liable to prosecution for not having the anti-dazzle apparatus maintained in efficient order. (To be continued next week.) Focusing head lamps. The board is 25ft. from the car and the discs are adjusted to the same height and spacing as the lamps themselves. * 25 | ||