Troubleshooting 101: Solving Your Car’s Electrical Problems

Troubleshooting 101: Solving Your Car’s Electrical Problems

With modern vehicles more computerized than ever, electrical issues can seem complex and overwhelming for the average owner to diagnose. Anything from a dead battery to faulty sensors can cause frustrating, difficult to pinpoint electrical gremlins. Equipping yourself with some fundamental troubleshooting knowledge can help you track down common glitches, saving garage bills.

Inspecting the Battery and Cables

The logical starting point when assessing any electrical fault is the fuse block housing under the dash. But before poking around here, first evaluate the main power source – your battery and cables. The experts at Clore Automotive recommend using a battery tester or have your battery load tested periodically to check overall charge condition and strength for reliable starts. Clean cables attached to battery terminal ends using a wire brush occasionally to eliminate corrosion that can inhibit power flow. If dealing with a no start issue coupled with dim or no interior lights, focus attention here first. 

Checking Fuses and Relays 

With battery and cables cleared as culprits, turn your attention to the multitude of fuses and relays protecting vehicle circuits. Use the fuse diagram on the underside of your fuse box lid to ensure you are assessing the appropriate slots. Pull suspected fuses straight out and view filaments inside to check for breaks. For primary systems like fuel pump, computer, starter, and charging circuits, also press on relays while getting a helper to crank or switch something on, feeling for an audible engagement click. If either component is faulty, slot in replacements of equal amperage from your onboard supply to restore function quickly.

Assessing Dashboard Warning Lights

Pay heed to that check engine light or ABS warning as dashboard alerts signify key sensors detecting trouble in associated systems. Use an OBD2 (onboard diagnostics) scanner tool plugged into your diagnostic port to extract the fault code stored in computer memory. Match the code with probable causes in your repair manual or via online community forums. This guides your inspection and testing of components within the flagged system.

Testing Electrical Components Directly

Sometimes electrical gremlins evade even computer fault codes. Here you may need to get hands on, testing components individually with a digital multimeter in areas like:

  • Lighting – Tail lights, brake lights and headlamps rely on clean bulb sockets for proper grounding. Use a multimeter to check for power at sockets with lights not working. Clean or replace corroded ground points if needed and fit new bulbs. 
  • Switches – Driver seat lumbar or power lock switch failed? Test switch continuity and voltage in both active and resting positions per your manual. Faulty modules get replaced easily via online parts suppliers. 
  • Sensors – Crankshaft position and camshaft sensors must send precise input to the computer for spark timing and fuel delivery. Unstable idle? Stalling? Check connector pins for corrosion before replacing sensors.

While somewhat daunting, methodically checking connections and probing wires with your meter helps isolate problematic components for replacement.

Seeking Professional Help

In some circumstances, despite strategic troubleshooting, you’ll need heavier diagnostic artillery. Throwing parts at temperamental electrical issues gets costly without pinpointing root causes. For issues that persist despite thorough testing, visit your repair shop. Experienced mechanics have access to professional grade scanners and lab scopes that allow conclusive diagnosis of faults. The small diagnosis fee prevents buying unnecessary parts while chasing problems. Before visiting though, compile notes on symptoms, troubleshooting steps tried, and suspect components to help efficiently guide the shop efforts toward resolving the issue.


The sophisticated electronics ingrained into vehicles nowadays occasionally suffer glitches. Be ready with fundamental troubleshooting knowledge. Methodically tracing symptoms helps restore proper electrical function while expanding your automotive knowledge, preventing reliance on professionals for every little thing.

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