Electrical Test Equipment History
Multimeters, lab scopes, test lights and network diagnostics in automotive use.
Why did stable power supplies become important for module programming?
Short answer: Module programming can take a long time, and a voltage drop can corrupt the software.
Module programming can take a long time, and a voltage drop can corrupt the software. As reprogramming became routine in the 2000s, stable programming power supplies became important shop tools.
Why did insulation testers become important with electrified vehicles?
Short answer: Insulation testers check whether high-voltage wiring and components are properly isolated.
Insulation testers check whether high-voltage wiring and components are properly isolated. They became important automotive tools with hybrids and EVs, although they had long been used in electrical trades. Use rated equipment and follow the service manual's safety steps.
Why did high-voltage gloves become part of automotive safety equipment?
Short answer: High-voltage insulating gloves, long used by electrical utilities, became part of automotive safety equipment as hybrids and EVs reached shops.
High-voltage insulating gloves, long used by electrical utilities, became part of automotive safety equipment as hybrids and EVs reached shops. Rated gloves protect technicians working on high-voltage components.
Why did CAT ratings on meters become important for hybrid and EV work?
Short answer: Meter CAT ratings indicate the measurement environments and transient voltages a meter is designed for.
Meter CAT ratings indicate the measurement environments and transient voltages a meter is designed for. They became more important in automotive work as hybrid and EV high-voltage systems reached shops. Follow the equipment maker's safety instructions when using it.
Why did back-probe pins become common in electrical diagnostics?
Short answer: Piercing wire insulation to test circuits can let moisture in and cause corrosion.
Piercing wire insulation to test circuits can let moisture in and cause corrosion. Back-probe pins that slide into connectors became common as technicians tested sensor and computer circuits without damaging wiring.
How did automotive electrical systems change from 6 volts to 12 volts?
Short answer: Many cars used 6-volt electrical systems until the 1950s.
Many cars used 6-volt electrical systems until the 1950s. Automakers moved to 12-volt systems to support higher-compression engines, more accessories and better starting, which changed batteries and test equipment.
Why did alternators replace generators?
Short answer: Alternators produce more current at low engine speeds than DC generators.
Alternators produce more current at low engine speeds than DC generators. They became common in the 1960s as vehicles added more electrical accessories.
How did battery testing evolve?
Short answer: Early battery tests used hydrometers and heavy carbon pile load testers.
Early battery tests used hydrometers and heavy carbon pile load testers. Electronic conductance testers later allowed quick testing without heavy loads, and they became common in parts stores and shops.
Why did wiring diagrams become more important over time?
Short answer: Early vehicles had simple electrical systems with few circuits.
Early vehicles had simple electrical systems with few circuits. As cars added computers, networks and accessories, detailed wiring diagrams became essential for diagnosis.
How did connector design change in vehicles?
Short answer: Older vehicles used simple bullet and spade connectors.
Older vehicles used simple bullet and spade connectors. Modern vehicles use sealed, locking connectors with many terminals, requiring special release tools and repair kits.
How did voltage regulators evolve?
Short answer: Early charging systems used electromechanical voltage regulators with contacts that needed adjustment.
Early charging systems used electromechanical voltage regulators with contacts that needed adjustment. Solid-state regulators, often built into the alternator, replaced them, and later the engine computer took over charging control on many vehicles.
Why were analog voltmeters and ammeters common in older shops?
Short answer: Before digital meters, technicians used analog meters with moving needles to test batteries, charging and starting systems.
Before digital meters, technicians used analog meters with moving needles to test batteries, charging and starting systems. Many shop testers combined voltmeters, ammeters and carbon piles in one console.
How did automotive fuses evolve?
Short answer: Older vehicles used glass tube fuses, which were replaced by blade-type fuses in the late 1970s and 1980s.
Older vehicles used glass tube fuses, which were replaced by blade-type fuses in the late 1970s and 1980s. Blade fuses were easier to identify and replace, and smaller versions followed.
When did fusible links and circuit breakers appear in vehicle wiring?
Short answer: Fusible links protected main wiring circuits, and circuit breakers protected some accessories.
Fusible links protected main wiring circuits, and circuit breakers protected some accessories. They became common in mid-twentieth-century vehicles as electrical loads increased.
How did electronic ignition change electrical testing?
Short answer: Electronic ignition replaced breaker points in the 1970s.
Electronic ignition replaced breaker points in the 1970s. Technicians needed meters and testers to check pickup coils, ignition modules and coils instead of points and condensers.
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.