Table of contents: Checking voltage ↓ Finding a short circuit ↓ Checking the reliability of grounding ↓
To help you locate the source of the fault, electrical diagrams are provided at the end of this Chapter. Study them before you begin diagnostics.
Electrical system faults are usually caused by simple issues such as a bad connection, a blown fuse or a bad relay. Check these items first.
Checking voltage
Lack of voltage on an electrical component is most often caused by a poor connection. Check the circuit section between the battery and the electrical component for integrity using a voltmeter.
Finding a short circuit
To check for a short circuit, remove the fuse and connect a test light or voltmeter to the fuse connection terminals. There should be no voltage.
Move the wire being tested from side to side. If the light comes on, there is a short circuit. The same test can be performed on any piece of electrical equipment, even a switch.
Checking the reliability of grounding
Disconnect the battery and connect one wire of the test lamp with the power source to the "ground" and the other to the "ground" wire of the element being tested. If the lamp lights up, the ground is OK.