Automobile maintenace: Meters and gauges to PCs

Abstract

A utomobiles, at the beginning of the 20th century, had little more than a radiator mounted, alco- hol-filled thermometer and a crude speed- ometer. Magneto ignition was usually the extent of the electrical system. Regularly scheduled vehicle maintenance of- ten required disassem- bly and reassembly in an owner's barn or at re- tually a rheostat-driven fuel gauge, an electric temperature gauge, a zero-cen- tered ammeter, and an oil pressure gauge rounded out the gauge cluster. Vacuum-powered windshield wip- ers replaced hand-operated ones dur- ing this time. The intake manifold provided the vacuum source. Engine speed and throttle position governed manifold pressure, which was affected by engine internal wear. The wiper speed varied with engine speed and throttle position; wipers slowed during idle and aggressive acceleration. Many people relied on the operation of the wipers as an indicator of the internal engine condition. Mechanics used dipsticks to monitor engine condition, watching the oil's color, temperature, and odor for particles from metal wear and carbon from engine oil coking. Some mechanics even used taste to guess internal engine condition. During this period, performance, re- liability, and simplicity in operation greatly improved when distributor ig- nition replaced magneto ignition. The 6-V flooded cell storage battery and dc generator enabled the dc starter motor, which ended the hand-crank era. Elec- tric lamps replaced acetylene and kero- sene exterior lamps. Tube radios, with their unreliable vibrators producing quasi ac, became common. Zero-cen- tered ammeters were limited to indicat- ing current flow to or from a battery. Electro-mechanical current and voltage regulators often caused surprise dead batteries and electrolysis, contrib- uting to low electrolyte level and buildup of insulating lead sulfate on battery terminals. Modern Automobile Emerges