Repair knowledge base
These guides support the catalog with helpful explanations, safer diagnostic workflows, and internal links to relevant diagram packages.
A vehicle-specific diagnostic case file for a 2021 Toyota Corolla radio or display that restarts while driving, covering symptom capture, loaded power and ground checks, connector inspection, charging-system influence, and data-network testing order.
A focused repair note for a 2007 Ford Focus circuit with no power, covering the correct fuse-panel path, both-side fuse testing, battery and ignition feeds, loaded voltage-drop checks, and safe short-circuit diagnosis.
A concise repair note for a completely dead factory or replacement radio in a 2005 Ford F-250 Super Duty, covering battery feed, key-switched power, grounds, connector condition, and equipped-system differences.
A vehicle-specific diagnostic case file for a 2006 GMC Envoy with several electrical systems failing together, covering battery feeds, fuse-block inputs, ignition-switched power, ground distribution, data lines, and loaded voltage-drop testing.
A focused repair note for one turn signal that flashes too fast, covering failed or incorrect bulbs, LED load mismatch, lamp sockets, shared grounds, trailer splices, BCM outputs, and connector voltage-drop checks.
A vehicle-specific diagnostic case file for a 2010 Dodge Charger that will not crank, covering the engine-compartment Integrated Power Module, 30A starter fuse, start request, relay control, starter solenoid feed, battery cables, and grounds.
A short repair note for HVAC blower motors that only work on high speed, covering resistor packs, blower control modules, speed switches, relay bypass paths, melted connectors, motor current, and ground checks.
A diagnostic case file for a radio that resets, loses presets, or only works with the key on after installation, covering constant B+, accessory power, ground, fuse taps, CAN wake-up, and connector pin checks.
A short repair note for reverse lights that do not turn on, covering fuse feed, transmission range switch or BCM input, reverse lamp output, rear connector, bulb socket, and ground checks.
A diagnostic case file for an A/C compressor clutch that will not engage, covering HVAC request, pressure switch or sensor input, PCM approval, relay control, clutch coil feed, and ground testing.
A short diagnostic note for a gear shifter stuck in Park, covering brake switch input, stop-lamp fuse feed, park position signal, BCM or relay release output, shift lock solenoid, and ground checks.
A practical stop-lamp diagnostic guide for brake lights that do not work while tail lights still operate, covering brake switch power, fuses, BCM or relay output, rear lamp connectors, grounds, and trailer wiring faults.
A short diagnostic note for trailer running lights, brake lights, and turn signals with no power, covering tow-vehicle fuses, 4-pin and 7-pin connectors, grounds, and voltage-drop checks.
A practical no-sound diagnostic guide for factory radio systems covering amplifier enable, speaker outputs, CAN wake-up, radio fuses, ground paths, and connector pinout checks.
A short repair note for scan tool no-power and no-communication faults using OBD2 DLC pinout, fuse feed, chassis ground, signal ground, CAN, and exact vehicle wiring diagrams.
A practical crank-no-start diagnostic guide for fuel pump relay circuits, fuse feeds, PCM command, inertia switch paths, pump voltage, connector checks, and ground testing.
A focused no-crank workflow for the 2008 Ford E350 Super Duty using power distribution, starting and charging, ground, shift-interlock, and anti-theft circuit references.
A practical cooling fan diagnosis guide for overheating, fan-not-working, fan-always-on, and A/C condenser fan faults using relay, fuse, PCM command, sensor, and ground checks.
Use a power window wiring diagram to separate switch, motor, door harness, master switch, BCM, fuse, relay, and ground faults before replacing parts.
A no-start workflow for crank sensor circuits covering two-wire and three-wire sensors, PCM pinouts, reference voltage, signal, ground, shielding, and harness testing.
A charging system diagnostic guide for alternator output, fusible links, sense wires, PCM control, LIN communication, grounds, and battery warning light faults.
Learn why high-intent searches like ECU pinout, BCM connector view, fuse box diagram, and harness color code often lead to faster automotive electrical diagnosis than generic wiring diagram searches.
A practical horn electrical diagnosis guide for no-horn, weak horn, and intermittent horn faults using fuse, relay, switch, clockspring, BCM, and ground circuit references.
Safety-first guidance for reading airbag and SRS wiring diagrams, identifying yellow connectors, avoiding unsafe probing, and understanding crash sensor and module circuits.
A clear glossary of essential car electrical terms, from voltage drop and ground reference to relay contacts, splices, CAN bus, pull-up circuits, and PWM signals.
The core skills technicians need to diagnose vehicle wiring faults: reading diagrams, voltage-drop testing, connector inspection, relay logic, scan data, and safe module testing.
A practical short-circuit workflow for fuses that keep blowing, including load isolation, connector separation, harness rub points, and safe current-limited testing.
How to approach communication codes with wiring diagrams, including CAN high/CAN low checks, terminating resistance, module feeds, and network branch isolation.
A real-world approach to battery drain testing using fuse maps, module sleep logic, relay feeds, and wiring diagrams to identify the circuit that stays awake.
A step-by-step headlight circuit workflow covering fuses, relays, BCM control, ground points, connector heat damage, and left-right comparison tests.
A practical guide to matching year, make, model, body variant, and electrical system so the repair diagram fits the vehicle in front of you.
How to use an air conditioning wiring diagram to separate compressor clutch faults, blower motor faults, pressure switch issues, and control-side problems.
A clean diagnostic path for no-crank and crank-no-start complaints using starter, ignition, fuel, ECM, relay, and ground circuit references.
Understand the diagram details that matter most during repair: connector IDs, ground points, fuse feeds, relay contacts, splice points, and page-to-page references.
Use ABS wiring diagrams to understand wheel speed sensor circuits, module power, brake switch input, warning lamp logic, and ground paths.
Workshop notes
Every guide starts with a specific electrical symptom, separates the circuit into testable sections, and points to the matching diagrams. Confirm the exact vehicle configuration and follow the applicable service precautions before probing a connector or bypassing a component.
