diagnose-electrical-fault

diagnose-electrical-fault is a skill for Claude Code from jeffreytse/grimoire-core. It costs 62 tokens per session (1,455 once invoked), scanned A, original, MIT.

A step-by-step guide for finding faults in a vehicle's electrical circuits and components. OBD-II is the standard car diagnostic system, and a multimeter measures electrical values such as voltage and continuity.

In plain words
What is it for?
Use it to inspect wiring and components, read diagnostic codes, and test vehicle circuits.
Why use it?
It helps locate the actual cause of a blown fuse, warning light, failed accessory, or intermittent problem before parts are replaced.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: positional $N argument.

Part of the grimoire-automotive plugin — 16 skills shipped together

Good fit Use it to inspect wiring and components, read diagnostic codes, and test vehicle circuits.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jeffreytse/grimoire-core/diagnose-electrical-fault
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add jeffreytse/grimoire-core --skill diagnose-electrical-fault
Clone the repo
git clone --depth 1 https://github.com/jeffreytse/grimoire-core

Made for: Claude Code.

Or install grimoire-automotive, the plugin that ships this one along with the rest of its 16 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for diagnose-electrical-fault

README.md
[![agentmods](https://agentmods.dev/badge/skills/jeffreytse/grimoire-core/diagnose-electrical-fault/github.svg)](https://agentmods.dev/skills/jeffreytse/grimoire-core/diagnose-electrical-fault)
Your own site
<a href="https://agentmods.dev/skills/jeffreytse/grimoire-core/diagnose-electrical-fault"><img src="https://agentmods.dev/badge/skills/jeffreytse/grimoire-core/diagnose-electrical-fault/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for diagnose-electrical-fault

Your own site · 80×15
<a href="https://agentmods.dev/skills/jeffreytse/grimoire-core/diagnose-electrical-fault"><img src="https://agentmods.dev/badge/skills/jeffreytse/grimoire-core/diagnose-electrical-fault.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,455 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00062 $0.01455
Opus 5 $0.00031 $0.00727
Sonnet 5 $0.00012 $0.00291
Haiku 4.5 $0.00006 $0.00145

Measured 11d ago against content hash 1c82abf24560, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

diagnose-electrical-fault scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/automotive/troubleshooting/skills/diagnose-electrical-fault/SKILL.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Diagnose Electrical Fault

Isolate an automotive electrical fault to a specific component or circuit using OBD-II codes, multimeter voltage and continuity tests, and systematic visual inspection — before replacing any parts.

Why This Is Best Practice

Why best: Systematic circuit-level diagnosis (OBD-II code retrieval, then circuit and component testing) isolates the actual fault instead of guessing, avoiding costly unnecessary part replacement. Adopted by: ASE A6 Electrical/Electronic Systems is a standalone certification reflecting the complexity of modern vehicle electrical systems. Professional diagnostic procedures (per Bosch Automotive Handbook and OEM service manuals) require OBD-II code retrieval and circuit testing before part replacement. AutoZone, O'Reilly, and most parts stores offer free OBD-II scanning — reducing shotgun part replacement. Impact: Modern vehicles have 50–100 Electronic Control Units (ECUs) controlling everything from emissions to comfort features. A "random" symptom (intermittent stall, flickering dash) is rarely random — it has a traceable electrical cause. Replacing parts without testing (the "swapperoo" method) costs $100–$1,000 in unnecessary parts and often doesn't fix the problem. A multimeter and 30 minutes of methodical testing identifies the specific failed component.

Steps

1. Read and record OBD-II codes first

OBD-II codes are the fastest path to circuit-level information:

  • Use an OBD-II scanner (inexpensive codes-only reader, or a professional bi-directional scanner)
  • Connect to the OBD-II port (usually under the dash, driver's side)
  • Record ALL codes — both current (active) and pending/history codes
  • Do not clear codes before recording (clearing deletes symptom history)

OBD-II code format: P (powertrain), B (body), C (chassis), U (network) + 4 digits.

  • P0xxx: generic powertrain codes (cross-manufacturer)
  • P1xxx: manufacturer-specific

A code points to a circuit, not always a component. P0300 (random misfire) does not mean "replace coils" — it means test the ignition system circuit. P0128 (coolant temp below threshold) usually means a stuck-open thermostat, not a sensor.

Read the full file on GitHub · 95 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 95 lines · 62 tokens per session scan A 1c82abf24560

Subscribe to this mod's changes

diagnose-electrical-fault is a skill published in the GitHub repository jeffreytse/grimoire-core (4 stars, last pushed 23d ago), licensed MIT. It adds 62 tokens to every session and 1,455 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.