LED Test Light

A test light is an inexpensive tool used to perform many simple electrical tests that would otherwise require a multimeter. It lights to indicate when there is voltage potential between any two test-points in a circuit.

With one probe contacting the battery negative (-) terminal or a known ground connection, the other probe can be used to check for voltage at other points in the circuit. The test light will light when the test probe contacts a voltage source, and current flows from the voltage source to ground.

With one probe contacting a known source of voltage, the other probe can be used to check for continuity to ground at other points in the circuit. Current will flow and the test light will light when the test-point provides the known voltage source with a path to ground.

LED Test Light (US1115)
Used to check for voltage reaching components or when searching for faults in a circuit.

Voltage range: 3 to 48 VDC


CAUTION: A common test light (with incandescent bulb) may no longer be used. The bulb's high current draw will damage sensitive electronic components.







NOTE This tool has been superseded by Audi Special Tool VAG1527B, Voltage Tester. (US1115 is still considered an acceptable equivalent to VAG1527B).


Voltage Tester (VAG1527B)
Order Number: TAG 152 7B0 28 ZEL
Two-pole voltage tester with two LEDs (light emitting diodes), suitable for measuring from 3 to 48 volts DC or AC.

When used to test DC circuits, the positive (+) or negative (-) LED will light, depending on polarity. When used to test AC circuits, both LEDs will light.

Supplied with banana clip and detachable probe-can be used directly with VAG1598 Test Box.

For troubleshooting all common electrical and electronic components in automobiles. Safe for testing electronic components and circuits because of extremely low current consumption (1.5 mA maximum).

Voltage range: 3 to 48 volts (AC or DC)


CAUTION: A common test light (with incandescent bulb) may no longer be used. The bulb's high current draw will damage sensitive electronic components.








NOTE This tool supersedes Audi Special Tool US1115 LED Test Light.


Making An LED Test Light
A lower-cost alternative to buying an LED test light such as US1115 or VAG1527B is to make one, using parts available from most any electronics supply outlet.

Assemble the components as shown. Use a needle nose plier to hold the parts and to act as a heat dam while soldering. Insulate the connections with heat-shrinkable tubing or electrical tape.







Do-it-yourself LED test light for safely testing sensitive solid-state circuits.

Parts:
1. LED (1)
2. 1/4 watt, 330 Ohm resistor (1)
3. Alligator clips (2)
4. Wire, Solder and Soldering Iron
5. Heat-shrinkable tubing or electrical tape