G-body Automotive Electrical Troubleshooting Manual

By Author: Ron West
Total Articles: 3495
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Troubleshooting an Electrical problem: Although for most of us it is an uphill task, but keeping a few rules in mind, it becomes a cakewalk, well, almost.

· A source of power is an essential for every circuit.
· All circuits require continuity
· In general, electrical devices require a minimum voltage for proper functioning

Also note that the root causes for most electrical problems are zero or very low voltage, or loss of continuity in connection.

Before we get down to troubleshooting the actual problem, we will need a Wiring Diagram of the electrical system. These wiring diagrams can be of two kinds: a block diagram (this entails the system-components and their inter-relations) and a schematic diagram.

Safety is the best policy!

· Avoid giving or receiving jump-starts from the Ignition Engines that possess computer-controlled equipment. This is done to eliminate the chances of damage of voltage spikes.
· The battery must be disconnected when doing electrical repairs or while replacing electrical (or electronic) component. This eliminates an accidental ...
... short.
· One must remain careful when probing wires. An electrical tape must be used to cover the hole that is made while probing a wire.

Tool-up!

· A test light: This looks like a screwdriver with a pointed end. There is a bulb present in the handle which lights up if there is power present.
· A volt/amp/ohm meter: A digital meter or an analog meter. Your choice.
· A set of jumper wires pre-made in different lengths with clips: Used when bypassing a section of harness. This helps to isolate the problem area.

Let's get started!

· The load point in the circuit is the element that a circuit is meant to power. Check for presence of voltage. Suppose no voltage is found at the load point. Bravo! We are one step closer to the problem. Check the fuse, circuit breaker that protects the circuit, or the power relay that supplies voltage to the circuit. Check circuit breaker by bypassing it with a jumper wire. If the circuit works when you bypass the circuit breaker, you have isolated the problem. Replace the circuit breaker.
· Electrical devices require a certain amount of voltage in order to operate. A light bulb will glow with reduced effect as the voltage drops. Checking the load point for battery voltage will tell you whether sufficient voltage is getting through or not. The battery should be at least 70 percent charged and read around 12.43 V (12.66 V is fully charged) on the voltmeter. If the battery is low, it should be recharged and tested.
· Cleaning and tightening battery cables and ground straps also helps in some cases.

Keeping these points in mind would help you troubleshoot successfully.