LED Test Light
Test LightA 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 (GND) 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 (GND).
With one probe contacting a known source of Voltage, the other probe can be used to check for continuity to ground (GND) 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 (GND).
CAUTION: A common test tight (with incandescent bulb) may no longer be used. The bulb's high current draw will damage sensitive electronic components.
LED Test Light (US 1115)
LED Test Light:
Used to check for Voltage reaching components or when searching for malfunctions in a circuit.
Voltage range: 3 to 48 Volts DC
NOTE: This tool has been superseded by Special Tool VAG 1527B, LED Tester. (US 1115 is still considered an acceptable equivalent to VAG 1527B).
LED Tester (VAG 1527B)
LED Test Light:
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 VAG 1598 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)
NOTE: This tool supersedes Special Tool US 1115 LED Test Light.
Making an LED Test Light
LED Test Light:
A lower-cost alternative to buying an LED Test Light such as US 1115 or VAG 1527B is to make one, using parts available from most any electronics supply outlet.
Assemble the components as shown. Use needle nose pliers to hold the parts and to act as a heat dam while soldering. Insulate the connections with heat-shrinkable tubing or electrical tape.
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